docs: def message(message, name=None):
      """ Convenience decorator that applies [`Msg()`](#msg) to a callable.
  
      ```python
      from good import Schema, message
  
      @message(u'Need a number')
      def intify(v):
          return int(v)
      ```
  
      :param message: Error message to use instead
      :type message: unicode
      :param name: Override schema name as well. See [`name`](#name).
      :type name: None|unicode
      :return: decorator
      :rtype: callable
      """
      def decorator(func):
          wf = update_wrapper(Msg(func, message), func)
          if name:
              wf.name = name
          return wf
      return decorator