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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _serialize(self):
 """ Serialize the ResponseObject. Returns a webob `Response` object. """


        # Do something appropriate if the response object is unbound
        if self._defcode is None:
            raise exceptions.UnboundResponse()

        # Build the response
        resp = self.response_class(request=self.req, status=self.code,
                                   headerlist=self._headers.items())

        # Do we have a body?
        if self.result:
            resp.content_type = self.content_type
            resp.body = self.serializer(self.result)

        # Return the response
        return resp