def METHOD_NAME(self, uri, http_method='GET', body=None,
                               headers=None):
    """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.
    """
    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}