def METHOD_NAME(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.METHOD_NAME(
        request, self.default_token_type)