'Accept input from the user.
:param str message: message to display to the user
:returns: tuple of (`code`, `input`) where
`code` - str display exit code
`input` - str of the user\'s input
:rtype: tuple
:raises errors.MissingCommandlineFlag: if there was no default'

def input(self, message, default=None, cli_flag=None, **unused_kwargs):

    if (default is None):
        self._interaction_fail(message, cli_flag)
    else:
        return (OK, default)
