contract Pausable is Ownable {
  event Pause();
  event Unpause();
  event NotPausable();

  bool public paused = false;
  bool public canPause = true;

  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused || msg.sender == owner);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
     * @dev called by the owner to pause, triggers stopped state
     **/
    function pause() onlyOwner whenNotPaused public {
        require(canPause == true);
        paused = true;
        emit Pause();
    }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    require(paused == true);
    paused = false;
    emit Unpause();
  }
  
  /**
     * @dev Prevent the token from ever being paused again
     **/
    function notPausable() onlyOwner public{
        paused = false;
        canPause = false;
        emit NotPausable();
    }
}
/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
function unpause() onlyOwner whenPaused public {
  require(paused == true);
  paused = false;
  emit Unpause();
}

/**
 * @dev called by the owner to unpause, returns to normal state
 */