@staticmethod
def _handle_twofactor(message=''):
    """ Called when SteamGuard requires two-factor authentication..
        Asks the user to enter the code.

        Args:
            message: Optional. A message from Steam service.

        Returns:
            A string containing the code.
        """
    print('SteamGuard requires mobile authentication...')
    twofactorcode = input('Please enter the code sent to your phone: ')
    twofactorcode.upper()
    return twofactorcode
