NexusWealthToken

{{
  "language": "Solidity",
  "sources": {
    "NexusWealthToken.sol": {
      "content": "// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Pausable.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Permit.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Votes.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/Nonces.sol"; 

/**
 * @title NexusWealthToken
 * @notice ERC20 with governance, blacklist, and PRESALE PAUSE functionality.
 * @dev Enhanced with presale-specific pause that allows purchases but blocks transfers
 * Compatible with OpenZeppelin Contracts v5.x
 */
contract NexusWealthToken is
    ERC20,
    ERC20Burnable,
    ERC20Pausable,
    ERC20Permit,
    ERC20Votes,
    Ownable,
    ReentrancyGuard
{
    uint8 private _customDecimals;
    uint256 public maxSupply;
    uint256 public totalMinted;
    uint256 public totalBurned;

    mapping(address => bool) public isBlacklisted;

    // === Blacklist Operators ===
    mapping(address => bool) public blacklistOperators;
    event BlacklistOperatorUpdated(address indexed operator, bool status);
    event AddressBlacklisted(address indexed user, bool status);

    // === Presale Pause Feature ===
    bool public presalePauseEnabled;
    address public presaleContract;
    mapping(address => bool) public presalePauseWhitelist;
    
    event PresalePauseEnabled();
    event PresalePauseDisabled();
    event PresaleContractUpdated(address indexed oldContract, address indexed newContract);
    event PresalePauseWhitelistUpdated(address indexed account, bool status);

    enum VoteType { Against, For, Abstain }

    struct Proposal {
        address proposer;
        string  description;
        uint256 snapshotBlock;
        uint256 startBlock;
        uint256 endBlock;
        uint256 forVotes;
        uint256 againstVotes;
        uint256 abstainVotes;
        bool    executed;
        bool    canceled;
        address[] targets;
        uint256[] values;
        bytes[] calldatas;
        uint256 eta;  // Execution time (for timelock)
    }

    mapping(uint256 => Proposal) public proposals;
    mapping(uint256 => mapping(address => bool)) public hasVoted;
    uint256 public proposalCount;
    uint256 public constant MIN_EXECUTION_DELAY = 14 days;
    uint256 public constant MAX_EXECUTION_DELAY = 30 days;

    uint256 public proposalThreshold;
    uint256 public votingDelay;
    uint256 public votingPeriod;
    uint256 public quorumNumerator;
    uint256 public constant QUORUM_DENOMINATOR = 10_000;
    uint256 public constant MAX_BATCH_SIZE = 100;

    event ProposalCreated(uint256 indexed id, address indexed proposer, uint256 snapshotBlock, uint256 startBlock, uint256 endBlock, string description);
    event VoteCast(uint256 indexed id, address indexed voter, VoteType support, uint256 weight);
    event ProposalCanceled(uint256 indexed id);
    event ProposalQueued(uint256 indexed id, uint256 eta);
    event ProposalExecuted(uint256 indexed id);

    constructor(
        string memory name,
        string memory symbol,
        uint8 decimals_,
        uint256 _maxSupply,
        uint256 _initialSupply
    )
        ERC20(name, symbol)
        ERC20Permit(name)
        Ownable(msg.sender)
    {
        _customDecimals = decimals_;
        maxSupply = _maxSupply * 10 ** _customDecimals;
        require(_initialSupply * 10 ** _customDecimals <= maxSupply, "Initial supply exceeds max");
        _mint(msg.sender, _initialSupply * 10 ** _customDecimals);
        totalMinted = _initialSupply * 10 ** _customDecimals;

        proposalThreshold = 0;
        votingDelay = 0;
        votingPeriod = 45_000;
        quorumNumerator = 400;
        
        // Initialize presale pause as disabled
        presalePauseEnabled = false;
    }

    // ===== Admin setters =====
    function setBlacklistOperator(address operator, bool status) external onlyOwner {
        blacklistOperators[operator] = status;
        emit BlacklistOperatorUpdated(operator, status);
    }

    // ===== Presale Pause Functions =====
    /**
     * @notice Set the presale contract address
     * @param _presaleContract Address of the presale contract
     */
    function setPresaleContract(address _presaleContract) external onlyOwner {
        require(_presaleContract != address(0), "Zero address not allowed");
        address oldContract = presaleContract;
        presaleContract = _presaleContract;
        emit PresaleContractUpdated(oldContract, _presaleContract);
    }

    /**
     * @notice Enable presale pause mode - allows only presale purchases, blocks transfers
     */
    function enablePresalePause() external onlyOwner {
        require(presaleContract != address(0), "Presale contract not set");
        presalePauseEnabled = true;
        emit PresalePauseEnabled();
    }

    /**
     * @notice Disable presale pause mode - re-enables normal transfers
     */
    function disablePresalePause() external onlyOwner {
        presalePauseEnabled = false;
        emit PresalePauseDisabled();
    }

    /**
     * @notice Add or remove address from presale pause whitelist
     * @param account Address to whitelist/unwhitelist
     * @param status True to whitelist, false to remove
     */
    function setPresalePauseWhitelist(address account, bool status) external onlyOwner {
        require(account != address(0), "Cannot whitelist zero address");
        presalePauseWhitelist[account] = status;
        emit PresalePauseWhitelistUpdated(account, status);
    }

    /**
     * @notice Batch whitelist multiple addresses
     * @param accounts Array of addresses to whitelist
     * @param status True to whitelist all, false to remove all
     */
    function setPresalePauseWhitelistBatch(address[] calldata accounts, bool status) external onlyOwner {
        require(accounts.length > 0 && accounts.length <= MAX_BATCH_SIZE, "Invalid batch size");
        
        for (uint256 i = 0; i < accounts.length; i++) {
            require(accounts[i] != address(0), "Zero address in batch");
            presalePauseWhitelist[accounts[i]] = status;
            emit PresalePauseWhitelistUpdated(accounts[i], status);
        }
    }

    /**
     * @notice Check if presale pause is active
     */
    function isPresalePaused() external view returns (bool) {
        return presalePauseEnabled;
    }

    // ===== Blacklist management =====
    modifier onlyBlacklistAdmin() {
        require(msg.sender == owner() || blacklistOperators[msg.sender], "Not authorized");
        _;
    }

    function setBlacklistStatus(address user, bool status) external onlyBlacklistAdmin {
        require(user != address(0), "Cannot blacklist zero address");
        isBlacklisted[user] = status;
        emit AddressBlacklisted(user, status);
    }

    // ===== ERC20 controls =====
    function decimals() public view override returns (uint8) { return _customDecimals; }
    function pause() external onlyOwner { _pause(); }
    function unpause() external onlyOwner { _unpause(); }

    /**
     * @notice Mint new tokens (up to maxSupply)
     * @param to Address to receive minted tokens
     * @param amount Amount of tokens to mint
     */
    function mint(address to, uint256 amount) external onlyOwner {
        require(to != address(0), "Cannot mint to zero address");
        require(totalSupply() + amount <= maxSupply, "Exceeds max supply");
        _mint(to, amount);
        totalMinted += amount;
    }

    /**
     * @notice Burn tokens (inherited from ERC20Burnable)
     * @dev Users can burn their own tokens, reduces total supply
     */
    function burn(uint256 amount) public override {
        super.burn(amount);
        totalBurned += amount;
    }

    /**
     * @notice Burn tokens from another account (requires allowance)
     * @param account Address to burn tokens from
     * @param amount Amount of tokens to burn
     */
    function burnFrom(address account, uint256 amount) public override {
        super.burnFrom(account, amount);
        totalBurned += amount;
    }

    // ===== Governance API =====
    function quorum(uint256 ) public view returns (uint256) {
        return (totalSupply() * quorumNumerator) / QUORUM_DENOMINATOR;
    }

    function setVotingParams(uint256 _threshold, uint256 _delay, uint256 _period, uint256 _quorumNumerator)
        external
        onlyOwner
    {
        require(_quorumNumerator >= 100 && _quorumNumerator <= QUORUM_DENOMINATOR, "Invalid quorum");
        require(_period >= 6_500 && _period <= 200_000, "Invalid period");
        require(_delay <= 50_000, "Delay too long");
        require(_threshold <= maxSupply / 100, "Threshold too high");
        
        proposalThreshold = _threshold;
        votingDelay = _delay;
        votingPeriod = _period;
        quorumNumerator = _quorumNumerator;
    }

    function createProposal(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        string memory description
    ) external returns (uint256 id) {
        require(getPastVotes(msg.sender, block.number - 1) >= proposalThreshold, "threshold");
        require(targets.length == values.length && targets.length == calldatas.length, "length mismatch");
        require(targets.length > 0, "no actions");
        require(targets.length <= 10, "too many actions");
        
        // Prevent governance from transferring ownership
        bytes4 transferOwnershipSelector = bytes4(keccak256("transferOwnership(address)"));
        for (uint256 i = 0; i < calldatas.length; i++) {
            require(calldatas[i].length < 4 || bytes4(calldatas[i]) != transferOwnershipSelector, 
                    "governance cannot transfer ownership");
        }
        
        id = ++proposalCount;
        uint256 snap = block.number;
        uint256 start = snap + votingDelay;
        uint256 end = start + votingPeriod;
        
        Proposal storage p = proposals[id];
        p.proposer = msg.sender;
        p.description = description;
        p.snapshotBlock = snap;
        p.startBlock = start;
        p.endBlock = end;
        p.targets = targets;
        p.values = values;
        p.calldatas = calldatas;
        
        emit ProposalCreated(id, msg.sender, snap, start, end, description);
    }

    function castVote(uint256 id, VoteType support) external {
        Proposal storage p = proposals[id];
        require(p.proposer != address(0), "no proposal");
        require(!p.canceled && !p.executed, "finalized");
        require(block.number >= p.startBlock && block.number <= p.endBlock, "voting closed");
        require(!hasVoted[id][msg.sender], "already voted");

        uint256 weight = getPastVotes(msg.sender, p.snapshotBlock);
        require(weight > 0, "no voting power");
        hasVoted[id][msg.sender] = true;

        if (support == VoteType.For) p.forVotes += weight;
        else if (support == VoteType.Against) p.againstVotes += weight;
        else p.abstainVotes += weight;

        emit VoteCast(id, msg.sender, support, weight);
    }

    function state(uint256 id) public view returns (string memory) {
        Proposal storage p = proposals[id];
        if (p.canceled) return "Canceled";
        if (p.executed) return "Executed";
        if (block.number < p.startBlock) return "Pending";
        if (block.number <= p.endBlock) return "Active";
        uint256 turnout = p.forVotes + p.againstVotes + p.abstainVotes;
        if (turnout < quorum(p.snapshotBlock)) return "Defeated";
        if (p.forVotes <= p.againstVotes) return "Defeated";
        if (p.eta > 0 && block.timestamp < p.eta) return "Queued";
        if (p.eta > 0 && block.timestamp > p.eta + MAX_EXECUTION_DELAY) return "Expired";
        if (p.eta > 0) return "Ready";
        return "Succeeded";
    }

    function cancel(uint256 id) external {
        Proposal storage p = proposals[id];
        require(!p.canceled && !p.executed, "finalized");
        require(msg.sender == p.proposer || msg.sender == owner(), "not auth");
        p.canceled = true;
        emit ProposalCanceled(id);
    }

    function queue(uint256 id) external {
        Proposal storage p = proposals[id];
        require(!p.canceled && !p.executed, "finalized");
        require(p.eta == 0, "already queued");
        require(block.number > p.endBlock, "still active");
        uint256 turnout = p.forVotes + p.againstVotes + p.abstainVotes;
        require(turnout >= quorum(p.snapshotBlock), "no quorum");
        require(p.forVotes > p.againstVotes, "not passed");
        
        p.eta = block.timestamp + MIN_EXECUTION_DELAY;
        emit ProposalQueued(id, p.eta);
    }

    function execute(uint256 id) external payable nonReentrant {
        Proposal storage p = proposals[id];
        require(!p.canceled && !p.executed, "finalized");
        require(p.eta > 0, "not queued");
        require(block.timestamp >= p.eta, "timelock not met");
        require(block.timestamp <= p.eta + MAX_EXECUTION_DELAY, "execution expired");
        
        // Prevent governance from transferring ownership
        bytes4 transferOwnershipSelector = bytes4(keccak256("transferOwnership(address)"));
        for (uint256 i = 0; i < p.calldatas.length; i++) {
            require(p.calldatas[i].length < 4 || bytes4(p.calldatas[i]) != transferOwnershipSelector, 
                    "governance cannot transfer ownership");
        }
        
        p.executed = true;
        
        for (uint256 i = 0; i < p.targets.length; i++) {
            (bool success, bytes memory returndata) = p.targets[i].call{value: p.values[i]}(p.calldatas[i]);
            require(success, string(abi.encodePacked("execution failed at action ", _toString(i), ": ", _getRevertMsg(returndata))));
        }
        
        emit ProposalExecuted(id);
    }
    
    function _toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) return "0";
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
    
    function _getRevertMsg(bytes memory returndata) internal pure returns (string memory) {
        if (returndata.length < 68) return "execution reverted";
        assembly {
            returndata := add(returndata, 0x04)
        }
        return abi.decode(returndata, (string));
    }
    
    function getActions(uint256 id) external view returns (
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas
    ) {
        Proposal storage p = proposals[id];
        return (p.targets, p.values, p.calldatas);
    }

    // ===== Required overrides =====
    function _update(address from, address to, uint256 value)
        internal
        override(ERC20, ERC20Pausable, ERC20Votes)
    {
        // Check blacklist first
        if (from != address(0)) require(!isBlacklisted[from], "Sender blacklisted");
        if (to != address(0)) require(!isBlacklisted[to], "Recipient blacklisted");
        
        // Check presale pause mode (only if not fully paused)
        if (presalePauseEnabled && !paused()) {
            // Allow minting (from == address(0)) and burning (to == address(0))
            if (from != address(0) && to != address(0)) {
                // Check if this is an allowed transfer during presale pause
                bool isPresaleTransfer = (from == presaleContract);
                bool isSenderWhitelisted = presalePauseWhitelist[from];
                bool isRecipientWhitelisted = presalePauseWhitelist[to];
                
                require(
                    isPresaleTransfer || isSenderWhitelisted || isRecipientWhitelisted,
                    "Transfers paused: presale only"
                );
            }
        }
        
        super._update(from, to, value);
    }

    function nonces(address owner)
        public
        view
        override(ERC20Permit, Nonces)
        returns (uint256)
    {
        return super.nonces(owner);
    }
}
"
    },
    "@openzeppelin/contracts/utils/Nonces.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Nonces.sol)
pragma solidity ^0.8.20;

/**
 * @dev Provides tracking nonces for addresses. Nonces will only increment.
 */
abstract contract Nonces {
    /**
     * @dev The nonce used for an `account` is not the expected current nonce.
     */
    error InvalidAccountNonce(address account, uint256 currentNonce);

    mapping(address account => uint256) private _nonces;

    /**
     * @dev Returns the next unused nonce for an address.
     */
    function nonces(address owner) public view virtual returns (uint256) {
        return _nonces[owner];
    }

    /**
     * @dev Consumes a nonce.
     *
     * Returns the current value and increments nonce.
     */
    function _useNonce(address owner) internal virtual returns (uint256) {
        // For each account, the nonce has an initial value of 0, can only be incremented by one, and cannot be
        // decremented or reset. This guarantees that the nonce never overflows.
        unchecked {
            // It is important to do x++ and not ++x here.
            return _nonces[owner]++;
        }
    }

    /**
     * @dev Same as {_useNonce} but checking that `nonce` is the next valid for `owner`.
     */
    function _useCheckedNonce(address owner, uint256 nonce) internal virtual {
        uint256 current = _useNonce(owner);
        if (nonce != current) {
            revert InvalidAccountNonce(owner, current);
        }
    }
}
"
    },
    "@openzeppelin/contracts/utils/ReentrancyGuard.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/ReentrancyGuard.sol)

pragma solidity ^0.8.20;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If EIP-1153 (transient storage) is available on the chain you're deploying at,
 * consider using {ReentrancyGuardTransient} instead.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant NOT_ENTERED = 1;
    uint256 private constant ENTERED = 2;

    uint256 private _status;

    /**
     * @dev Unauthorized reentrant call.
     */
    error ReentrancyGuardReentrantCall();

    constructor() {
        _status = NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be NOT_ENTERED
        if (_status == ENTERED) {
            revert ReentrancyGuardReentrantCall();
        }

        // Any calls to nonReentrant after this point will fail
        _status = ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == ENTERED;
    }
}
"
    },
    "@openzeppelin/contracts/access/Ownable.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * The initial owner is set to the address provided by the deployer. This can
 * later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
"
    },
    "@openzeppelin/contracts/token/ERC20/extensions/ERC20Votes.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/ERC20Votes.sol)

pragma solidity ^0.8.20;

import {ERC20} from "../ERC20.sol";
import {Votes} from "../../../governance/utils/Votes.sol";
import {Checkpoints} from "../../../utils/structs/Checkpoints.sol";

/**
 * @dev Extension of ERC-20 to support Compound-like voting and delegation. This version is more generic than Compound's,
 * and supports token supply up to 2^208^ - 1, while COMP is limited to 2^96^ - 1.
 *
 * NOTE: This contract does not provide interface compatibility with Compound's COMP token.
 *
 * This extension keeps a history (checkpoints) of each account's vote power. Vote power can be delegated either
 * by calling the {Votes-delegate} function directly, or by providing a signature to be used with {Votes-delegateBySig}. Voting
 * power can be queried through the public accessors {Votes-getVotes} and {Votes-getPastVotes}.
 *
 * By default, token balance does not account for voting power. This makes transfers cheaper. The downside is that it
 * requires users to delegate to themselves in order to activate checkpoints and have their voting power tracked.
 */
abstract contract ERC20Votes is ERC20, Votes {
    /**
     * @dev Total supply cap has been exceeded, introducing a risk of votes overflowing.
     */
    error ERC20ExceededSafeSupply(uint256 increasedSupply, uint256 cap);

    /**
     * @dev Maximum token supply. Defaults to `type(uint208).max` (2^208^ - 1).
     *
     * This maximum is enforced in {_update}. It limits the total supply of the token, which is otherwise a uint256,
     * so that checkpoints can be stored in the Trace208 structure used by {Votes}. Increasing this value will not
     * remove the underlying limitation, and will cause {_update} to fail because of a math overflow in
     * {Votes-_transferVotingUnits}. An override could be used to further restrict the total supply (to a lower value) if
     * additional logic requires it. When resolving override conflicts on this function, the minimum should be
     * returned.
     */
    function _maxSupply() internal view virtual returns (uint256) {
        return type(uint208).max;
    }

    /**
     * @dev Move voting power when tokens are transferred.
     *
     * Emits a {IVotes-DelegateVotesChanged} event.
     */
    function _update(address from, address to, uint256 value) internal virtual override {
        super._update(from, to, value);
        if (from == address(0)) {
            uint256 supply = totalSupply();
            uint256 cap = _maxSupply();
            if (supply > cap) {
                revert ERC20ExceededSafeSupply(supply, cap);
            }
        }
        _transferVotingUnits(from, to, value);
    }

    /**
     * @dev Returns the voting units of an `account`.
     *
     * WARNING: Overriding this function may compromise the internal vote accounting.
     * `ERC20Votes` assumes tokens map to voting units 1:1 and this is not easy to change.
     */
    function _getVotingUnits(address account) internal view virtual override returns (uint256) {
        return balanceOf(account);
    }

    /**
     * @dev Get number of checkpoints for `account`.
     */
    function numCheckpoints(address account) public view virtual returns (uint32) {
        return _numCheckpoints(account);
    }

    /**
     * @dev Get the `pos`-th checkpoint for `account`.
     */
    function checkpoints(address account, uint32 pos) public view virtual returns (Checkpoints.Checkpoint208 memory) {
        return _checkpoints(account, pos);
    }
}
"
    },
    "@openzeppelin/contracts/token/ERC20/extensions/ERC20Permit.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/extensions/ERC20Permit.sol)

pragma solidity ^0.8.20;

import {IERC20Permit} from "./IERC20Permit.sol";
import {ERC20} from "../ERC20.sol";
import {ECDSA} from "../../../utils/cryptography/ECDSA.sol";
import {EIP712} from "../../../utils/cryptography/EIP712.sol";
import {Nonces} from "../../../utils/Nonces.sol";

/**
 * @dev Implementation of the ERC-20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[ERC-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC-20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712, Nonces {
    bytes32 private constant PERMIT_TYPEHASH =
        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");

    /**
     * @dev Permit deadline has expired.
     */
    error ERC2612ExpiredSignature(uint256 deadline);

    /**
     * @dev Mismatched signature.
     */
    error ERC2612InvalidSigner(address signer, address owner);

    /**
     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
     *
     * It's a good idea to use the same `name` that is defined as the ERC-20 token name.
     */
    constructor(string memory name) EIP712(name, "1") {}

    /// @inheritdoc IERC20Permit
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual {
        if (block.timestamp > deadline) {
            revert ERC2612ExpiredSignature(deadline);
        }

        bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));

        bytes32 hash = _hashTypedDataV4(structHash);

        address signer = ECDSA.recover(hash, v, r, s);
        if (signer != owner) {
            revert ERC2612InvalidSigner(signer, owner);
        }

        _approve(owner, spender, value);
    }

    /// @inheritdoc IERC20Permit
    function nonces(address owner) public view virtual override(IERC20Permit, Nonces) returns (uint256) {
        return super.nonces(owner);
    }

    /// @inheritdoc IERC20Permit
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view virtual returns (bytes32) {
        return _domainSeparatorV4();
    }
}
"
    },
    "@openzeppelin/contracts/token/ERC20/extensions/ERC20Pausable.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/ERC20Pausable.sol)

pragma solidity ^0.8.20;

import {ERC20} from "../ERC20.sol";
import {Pausable} from "../../../utils/Pausable.sol";

/**
 * @dev ERC-20 token with pausable token transfers, minting and burning.
 *
 * Useful for scenarios such as preventing trades until the end of an evaluation
 * period, or having an emergency switch for freezing all token transfers in the
 * event of a large bug.
 *
 * IMPORTANT: This contract does not include public pause and unpause functions. In
 * addition to inheriting this contract, you must define both functions, invoking the
 * {Pausable-_pause} and {Pausable-_unpause} internal functions, with appropriate
 * access control, e.g. using {AccessControl} or {Ownable}. Not doing so will
 * make the contract pause mechanism of the contract unreachable, and thus unusable.
 */
abstract contract ERC20Pausable is ERC20, Pausable {
    /**
     * @dev See {ERC20-_update}.
     *
     * Requirements:
     *
     * - the contract must not be paused.
     */
    function _update(address from, address to, uint256 value) internal virtual override whenNotPaused {
        super._update(from, to, value);
    }
}
"
    },
    "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/ERC20Burnable.sol)

pragma solidity ^0.8.20;

import {ERC20} from "../ERC20.sol";
import {Context} from "../../../utils/Context.sol";

/**
 * @dev Extension of {ERC20} that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
abstract contract ERC20Burnable is Context, ERC20 {
    /**
     * @dev Destroys a `value` amount of tokens from the caller.
     *
     * See {ERC20-_burn}.
     */
    function burn(uint256 value) public virtual {
        _burn(_msgSender(), value);
    }

    /**
     * @dev Destroys a `value` amount of tokens from `account`, deducting from
     * the caller's allowance.
     *
     * See {ERC20-_burn} and {ERC20-allowance}.
     *
     * Requirements:
     *
     * - the caller must have allowance for ``accounts``'s tokens of at least
     * `value`.
     */
    function burnFrom(address account, uint256 value) public virtual {
        _spendAllowance(account, _msgSender(), value);
        _burn(account, value);
    }
}
"
    },
    "@openzeppelin/contracts/token/ERC20/ERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC-20
 * applications.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;

    mapping(address account => mapping(address spender => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * Both values are immutable: they can only be set once during construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return 18;
    }

    /// @inheritdoc IERC20
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    /// @inheritdoc IERC20
    function balanceOf(address account) public view virtual returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `value`.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    /// @inheritdoc IERC20
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Skips emitting an {Approval} event indicating an allowance update. This is not
     * required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `value`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `value`.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }

    /**
     * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
     * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    /**
     * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
     * Relies on the `_update` mechanism
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }

    /**
     * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
     * Relies on the `_update` mechanism.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }

    /**
     * @dev Sets `value` as the allowance of `spender` over the `owner`'s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     *
     * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }

    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
     * `Approval` event during `transferFrom` operations.
     *
     * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
     * true using the following override:
     *
     * ```solidity
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * ```
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }

    /**
     * @dev Updates `owner`'s allowance for `spender` based on spent `value`.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance < type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(spender, currentAllowance, value);
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}
"
    },
    "@openzeppelin/contracts/utils/structs/Checkpoints.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (utils/structs/Checkpoints.sol)
// This file was procedurally generated from scripts/generate/templates/Checkpoints.js.

pragma solidity ^0.8.20;

import {Math} from "../math/Math.sol";

/**
 * @dev This library defines the `Trace*` struct, for checkpointing values as they change at different points in
 * time, and later looking up past values by block number. See {Votes} as an example.
 *
 * To create a history of checkpoints define a variable type `Checkpoints.Trace*` in your contract, and store a new
 * checkpoint for the current transaction block using the {push} function.
 */
library Checkpoints {
    /**
     * @dev A value was attempted to be inserted on a past checkpoint.
     */
    error CheckpointUnorderedInsertion();

    struct Trace224 {
        Checkpoint224[] _checkpoints;
    }

    struct Checkpoint224 {
        uint32 _key;
        uint224 _value;
    }

    /**
     * @dev Pushes a (`key`, `value`) pair into a Trace224 so that it is stored as the checkpoint.
     *
     * Returns previous value and new value.
     *
     * IMPORTANT: Never accept `key` as a user input, since an arbitrary `type(uint32).max` key set will disable the
     * library.
     */
    function push(
        Trace224 storage self,
        uint32 key,
        uint224 value
    ) internal returns (uint224 oldValue, uint224 newValue) {
        return _insert(self._checkpoints, key, value);
    }

    /**
     * @dev Returns the value in the first (oldest) checkpoint with key greater or equal than the search key, or zero if
     * there is none.
     */
    function lowerLookup(Trace224 storage self, uint32 key) internal view returns (uint224) {
        uint256 len = self._checkpoints.length;
        uint256 pos = _lowerBinaryLookup(self._checkpoints, key, 0, len);
        return pos == len ? 0 : _unsafeAccess(self._checkpoints, pos)._value;
    }

    /**
     * @dev Returns the value in the last (most recent) checkpoint with key lower or equal than the search key, or zero
     * if there is none.
     */
    function upperLookup(Trace224 storage self, uint32 key) internal view returns (uint224) {
        uint256 len = self._checkpoints.length;
        uint256 pos = _upperBinaryLookup(self._checkpoints, key, 0, len);
        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns the value in the last (most recent) checkpoint with key lower or equal than the search key, or zero
     * if there is none.
     *
     * NOTE: This is a variant of {upperLookup} that is optimized to find "recent" checkpoint (checkpoints with high
     * keys).
     */
    function upperLookupRecent(Trace224 storage self, uint32 key) internal view returns (uint224) {
        uint256 len = self._checkpoints.length;

        uint256 low = 0;
        uint256 high = len;

        if (len > 5) {
            uint256 mid = len - Math.sqrt(len);
            if (key < _unsafeAccess(self._checkpoints, mid)._key) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        uint256 pos = _upperBinaryLookup(self._checkpoints, key, low, high);

        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns the value in the most recent checkpoint, or zero if there are no checkpoints.
     */
    function latest(Trace224 storage self) internal view returns (uint224) {
        uint256 pos = self._checkpoints.length;
        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns whether there is a checkpoint in the structure (i.e. it is not empty), and if so the key and value
     * in the most recent checkpoint.
     */
    function latestCheckpoint(Trace224 storage self) internal view returns (bool exists, uint32 _key, uint224 _value) {
        uint256 pos = self._checkpoints.length;
        if (pos == 0) {
            return (false, 0, 0);
        } else {
            Checkpoint224 storage ckpt = _unsafeAccess(self._checkpoints, pos - 1);
            return (true, ckpt._key, ckpt._value);
        }
    }

    /**
     * @dev Returns the number of checkpoints.
     */
    function length(Trace224 storage self) internal view returns (uint256) {
        return self._checkpoints.length;
    }

    /**
     * @dev Returns checkpoint at given position.
     */
    function at(Trace224 storage self, uint32 pos) internal view returns (Checkpoint224 memory) {
        return self._checkpoints[pos];
    }

    /**
     * @dev Pushes a (`key`, `value`) pair into an ordered list of checkpoints, either by inserting a new checkpoint,
     * or by updating the last one.
     */
    function _insert(
        Checkpoint224[] storage self,
        uint32 key,
        uint224 value
    ) private returns (uint224 oldValue, uint224 newValue) {
        uint256 pos = self.length;

        if (pos > 0) {
            Checkpoint224 storage last = _unsafeAccess(self, pos - 1);
            uint32 lastKey = last._key;
            uint224 lastValue = last._value;

            // Checkpoint keys must be non-decreasing.
            if (lastKey > key) {
                revert CheckpointUnorderedInsertion();
            }

            // Update or push new checkpoint
            if (lastKey == key) {
                last._value = value;
            } else {
                self.push(Checkpoint224({_key: key, _value: value}));
            }
            return (lastValue, value);
        } else {
            self.push(Checkpoint224({_key: key, _value: value}));
            return (0, value);
        }
    }

    /**
     * @dev Return the index of the first (oldest) checkpoint with key strictly bigger than the search key, or `high`
     * if there is none. `low` and `high` define a section where to do the search, with inclusive `low` and exclusive
     * `high`.
     *
     * WARNING: `high` should not be greater than the array's length.
     */
    function _upperBinaryLookup(
        Checkpoint224[] storage self,
        uint32 key,
        uint256 low,
        uint256 high
    ) private view returns (uint256) {
        while (low < high) {
            uint256 mid = Math.average(low, high);
            if (_unsafeAccess(self, mid)._key > key) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }
        return high;
    }

    /**
     * @dev Return the index of the first (oldest) checkpoint with key greater or equal than the search key, or `high`
     * if there is none. `low` and `high` define a section where to do the search, with inclusive `low` and exclusive
     * `high`.
     *
     * WARNING: `high` should not be greater than the array's length.
     */
    function _lowerBinaryLookup(
        Checkpoint224[] storage self,
        uint32 key,
        uint256 low,
        uint256 high
    ) private view returns (uint256) {
        while (low < high) {
            uint256 mid = Math.average(low, high);
            if (_unsafeAccess(self, mid)._key < key) {
                low = mid + 1;
            } else {
                high = mid;
            }
        }
        return high;
    }

    /**
     * @dev Access an element of the array without performing bounds check. The position is assumed to be within bounds.
     */
    function _unsafeAccess(
        Checkpoint224[] storage self,
        uint256 pos
    ) private pure returns (Checkpoint224 storage result) {
        assembly {
            mstore(0, self.slot)
            result.slot := add(keccak256(0, 0x20), pos)
        }
    }

    struct Trace208 {
        Checkpoint208[] _checkpoints;
    }

    struct Checkpoint208 {
        uint48 _key;
        uint208 _value;
    }

    /**
     * @dev Pushes a (`key`, `value`) pair into a Trace208 so that it is stored as the checkpoint.
     *
     * Returns previous value and new value.
     *
     * IMPORTANT: Never accept `key` as a user input, since an arbitrary `type(uint48).max` key set will disable the
     * library.
     */
    function push(
        Trace208 storage self,
        uint48 key,
        uint208 value
    ) internal returns (uint208 oldValue, uint208 newValue) {
        return _insert(self._checkpoints, key, value);
    }

    /**
     * @dev Returns the value in the first (oldest) checkpoint with key greater or equal than the search key, or zero if
     * there is none.
     */
    function lowerLookup(Trace208 storage self, uint48 key) internal view returns (uint208) {
        uint256 len = self._checkpoints.length;
        uint256 pos = _lowerBinaryLookup(self._checkpoints, key, 0, len);
        return pos == len ? 0 : _unsafeAccess(self._checkpoints, pos)._value;
    }

    /**
     * @dev Returns the value in the last (most recent) checkpoint with key lower or equal than the search key, or zero
     * if there is none.
     */
    function upperLookup(Trace208 storage self, uint48 key) internal view returns (uint208) {
        uint256 len = self._checkpoints.length;
        uint256 pos = _upperBinaryLookup(self._checkpoints, key, 0, len);
        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns the value in the last (most recent) checkpoint with key lower or equal than the search key, or zero
     * if there is none.
     *
     * NOTE: This is a variant of {upperLookup} that is optimized to find "recent" checkpoint (checkpoints with high
     * keys).
     */
    function upperLookupRecent(Trace208 storage self, uint48 key) internal view returns (uint208) {
        uint256 len = self._checkpoints.length;

        uint256 low = 0;
        uint256 high = len;

        if (len > 5) {
            uint256 mid = len - Math.sqrt(len);
            if (key < _unsafeAccess(self._checkpoints, mid)._key) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        uint256 pos = _upperBinaryLookup(self._checkpoints, key, low, high);

        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns the value in the most recent checkpoint, or zero if there are no checkpoints.
     */
    function latest(Trace208 storage self) internal view returns (uint208) {
        uint256 pos = self._checkpoints.length;
        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns whether there is a checkpoint in the structure (i.e. it is not empty), and if so the key and value
     * in the most recent checkpoint.
     */
    function latestCheckpoint(Trace208 storage self) internal view returns (bool exists, uint48 _key, uint208 _value) {
        uint256 pos = self._checkpoints.length;
        if (pos == 0) {
            return (false, 0, 0);
        } else {
            Checkpoint208 storage ckpt = _unsafeAccess(self._checkpoints, pos - 1);
            return (true, ckpt._key, ckpt._value);
        }
    }

    /**
     * @dev Returns the number of checkpoints.
     */
    function length(Trace208 storage self) internal view returns (uint256) {
        return self._checkpoints.length;
    }

    /**
     * @dev Returns checkpoint at given position.
     */
    function at(Trace208 storage self, uint32 pos) internal view returns (Checkpoint208 memory) {
        return self._checkpoints[pos];
    }

    /**
     * @dev Pushes a (`key`, `value`) pair into an ordered list of checkpoints, either by inserting a new checkpoint,
     * or by updating the last one.
     */
    function _insert(
        Checkpoint208[] storage self,
        uint48 key,
        uint208 value
    ) private returns (uint208 oldValue, uint208 newValue) {
        uint256 pos = self.length;

        if (pos > 0) {
            Checkpoint208 storage last = _unsafeAccess(self, pos - 1);
            uint48 lastKey = last._key;
            uint208 lastValue = last._value;

            // Checkpoint keys must be non-decreasing.
            if (lastKey > key) {
                revert CheckpointUnorderedInsertion();
            }

            // Update or push new checkpoint
            if (lastKey == key) {
                last._value = value;
            } else {
                self.push(Checkpoint208({_key: key, _value: value}));
            }
            return (lastValue, value);
        } else {
            self.push(Checkpoint208({_key: key, _value: value}));
            return (0, value);
        }
    }

    /**
     * @dev Return the index of the first (oldest) checkpoint with key strictly bigger than the search key, or `high`
     * if there is none. `low` and `high` define a section where to do the search, with inclusive `low` and exclusive
     * `high`.
     *
     * WARNING: `high` should not be greater than the array's length.
     */
    function _upperBinaryLookup(
        Checkpoint208[] storage self,
        uint48 key,
        uint256 low,
        uint256 high
    ) private view returns (uint256) {
        while (low < high) {
            uint256 mid = Math.average(low, high);
            if (_unsafeAccess(self, mid)._key > key) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }
        return high;
    }

    /**
     * @dev Return the index of the first (oldest) checkpoint with key greater or equal than the search key, or `high`
     * if there is none. `low` and `high` define a section where to do the search, with inclusive `low` and exclusive
     * `high`.
     *
     * WARNING: `high` should not be greater than the array's length.
     */
    function _lowerBinaryLookup(
        Checkpoint208[] storage self,
        uint48 key,
        uint256 low,
        uint256 high
    ) private view returns (uint256) {
        while (low < high) {
            uint256 mid = Math.average(low, high);
            if (_unsafeAccess(self, mid)._key < key) {
                low = mid + 1;
            } else {
                high = mid;
            }
        }
        return high;
    }

    /**
     * @dev Access an element of the array without performing bounds check. The position is assumed to be within bounds.
     */
    function _unsafeAccess(
        Checkpoint208[] storage self,
        uint256 pos
    ) private pure returns (Checkpoint208 storage result) {
        assembly {
            mstore(0, self.slot)
            result.slot := add(keccak256(0, 0x20), pos)
        }
    }

    struct Trace160 {
        Checkpoint160[] _checkpoints;
    }

    struct Checkpoint160 {
        uint96 _key;
        uint160 _value;
    }

    /**
     * @dev Pushes a (`key`, `value`) pair into a Trace160 so that it is stored as the checkpoint.
     *
     * Returns previous value and new value.
     *
     * IMPORTANT: Never accept `key` as a user input, since an arbitrary `type(uint96).max` key set will disable the
     * library.
     */
    function push(
        Trace160 storage self,
        uint96 key,
        uint160 value
    ) internal returns (uint160 oldValue, uint160 newValue) {
        return _insert(self._checkpoints, key, value);
    }

    /**
     * @dev Returns the value in the first (oldest) checkpoint with key greater or equal than the search key, or zero if
     * there is none.
     */
    function lowerLookup(Trace160 storage self, uint96 key) internal view returns (uint160) {
        uint256 len = self._checkpoints.length;
        uint256 pos = _lowerBinaryLookup(self._checkpoints, key, 0, len);
        return pos == len ? 0 : _unsafeAccess(self._checkpoints, pos)._value;
    }

    /**
     * @dev Returns the value in the last (most recent) checkpoint with key lower or equal than the search key, or zero
     * if there is none.
     */
    function upperLookup(Trace160 storage self, uint96 key) internal view returns (uint160) {
        uint256 len = self._checkpoints.length;
        uint256 pos = _upperBinaryLookup(self._checkpoints, key, 0, len);
        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns the value in the last (most recent) checkpoint with key lower or equal than the search key, or zero
     * if there is none.
     *
     * NOTE: This is a variant of {upperLookup} that is optimized to find "recent" checkpoint (checkpoints with high
     * keys).
     */
    function upperLookupRecent(Trace160 storage self, uint96 key) internal view returns (uint160) {
        uint256 len = self._checkpoints.length;

        uint256 low = 0;
        uint256 high = len;

        if (len > 5) {
            uint256 mid = len - Math.sqrt(len);
            if (key < _unsafeAccess(self._checkpoints, mid)._key) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        uint256 pos = _upperBinaryLookup(self._checkpoints, key, low, high);

        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns the value in the most recent checkpoint, or zero if there are no checkpoints.
     */
    function latest(Trace160 storage self) internal view returns (uint160) {
        uint256 pos = self._checkpoints.length;
        return pos == 0 ? 0 : _unsafeAccess(self._checkpoints, pos - 1)._value;
    }

    /**
     * @dev Returns whether there is a checkpoint in the structure (i.e. it is not empty), and if so the key and value
     * in the most recent checkpoint.
     */
    function latestCheckpoint(Trace160 storage self) internal view returns (bool exists, uint96 _key, uint160 _value) {
        uint256 pos = self._checkpoints.length;
        if (pos == 0) {
            return (false, 0, 0);
        } else {
            Checkpoint160 storage ckpt = _unsafeAccess(self._checkpoints, pos - 1);
            return (true, ckpt._key, ckpt._value);
        }
    }

    /**
     * @dev Returns the number of checkpoints.
     */
    function length(Trace160 storage self) internal view returns (uint256) {
        return self._checkpoints.length;
    }

    /**
     * @dev Returns checkpoint at given position.
     */
    function at(Trace160 storage self, uint32 pos) internal view returns (Checkpoint160 memory) {
        return self._checkpoints[pos];
    }

    /**
     * @dev Pushes a (`key`, `value`) pair into an ordered list of checkpoints, either by inserting a new checkpoint,
     * or by updating the last one.
     */
    function _insert(
        Checkpoint160[] storage self,
        uint96 key,
        uint160 value