Extract response_type and route to the designated handler.

def create_authorization_response(self, uri, http_method='GET', body=None,
                                      headers=None, scopes=None, credentials=None):
        """Extract response_type and route to the designated handler."""
        request = Request(
            uri, http_method=http_method, body=body, headers=headers)
        request.scopes = scopes
        # TODO: decide whether this should be a required argument
        request.user = None     # TODO: explain this in docs
        for k, v in (credentials or {}).items():
            setattr(request, k, v)
        response_type_handler = self.response_types.get(
            request.response_type, self.default_response_type_handler)
        log.debug('Dispatching response_type %s request to %r.',
                  request.response_type, response_type_handler)
        return response_type_handler.create_authorization_response(
            request, self.default_token_type)