code: def get_realms_and_credentials(self, uri, http_method='GET', body=None,
                                     headers=None):
          
          request = self._create_request(uri, http_method=http_method, body=body,
                                         headers=headers)
  
          if not self.request_validator.verify_request_token(
                  request.resource_owner_key, request):
              raise errors.InvalidClientError()
  
          realms = self.request_validator.get_realms(
              request.resource_owner_key, request)
          return realms, {'resource_owner_key': request.resource_owner_key}
docs: Fetch realms and credentials for the presented request token.
  
          :param uri: The full URI of the token request.
          :param http_method: A valid HTTP verb, i.e. GET, POST, PUT, HEAD, etc.
          :param body: The request body as a string.
          :param headers: The request headers as a dict.
          :returns: A tuple of 2 elements.
                    1. A list of request realms.
                    2. A dict of credentials which may be useful in creating the
                    authorization form.