Bind a ResponseObject to a given action descriptor.  This
        updates the default HTTP response code and selects the
        appropriate content type and serializer for the response.

def _bind(self, _descriptor):
        """
        Bind a ResponseObject to a given action descriptor.  This
        updates the default HTTP response code and selects the
        appropriate content type and serializer for the response.
        """

        # If the method has a default code, use it
        self._defcode = getattr(_descriptor.method, '_wsgi_code', 200)

        # Set up content type and serializer
        self.content_type, self.serializer = _descriptor.serializer(self.req)