Pausable.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./Context.sol";


abstract contract Pausable is Context {
  
    event Paused(address account);

  
    event Unpaused(address account);

    bool private _paused;

 
    constructor () {
        _paused = false;
    }

  
    function paused() public view virtual returns (bool) {
        return _paused;
    }


    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }


    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

 
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

 
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
    
}