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Solidity

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20VotesComp.sol)
pragma solidity ^0.8.0;
import "./ERC20Votes.sol";
/**
* @dev Extension of ERC20 to support Compound's voting and delegation. This version exactly matches Compound's
* interface, with the drawback of only supporting supply up to (2^96^ - 1).
*
* NOTE: You should use this contract if you need exact compatibility with COMP (for example in order to use your token
* with Governor Alpha or Bravo) and if you are sure the supply cap of 2^96^ is enough for you. Otherwise, use the
* {ERC20Votes} variant of this module.
*
* This extension keeps a history (checkpoints) of each account's vote power. Vote power can be delegated either
* by calling the {delegate} function directly, or by providing a signature to be used with {delegateBySig}. Voting
* power can be queried through the public accessors {getCurrentVotes} and {getPriorVotes}.
*
* 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.
*
* _Available since v4.2._
*/
abstract contract ERC20VotesComp is ERC20Votes {
/**
* @dev Comp version of the {getVotes} accessor, with `uint96` return type.
*/
function getCurrentVotes(address account) external view virtual returns (uint96) {
return SafeCast.toUint96(getVotes(account));
}
/**
* @dev Comp version of the {getPastVotes} accessor, with `uint96` return type.
*/
function getPriorVotes(address account, uint256 blockNumber) external view virtual returns (uint96) {
return SafeCast.toUint96(getPastVotes(account, blockNumber));
}
/**
* @dev Maximum token supply. Reduced to `type(uint96).max` (2^96^ - 1) to fit COMP interface.
*/
function _maxSupply() internal view virtual override returns (uint224) {
return type(uint96).max;
}
}