'If there are more pages left in the query result, this asynchronously
starts fetching the next page.  If there are no pages left, :exc:`.QueryExhausted`
is raised.  Also see :attr:`.has_more_pages`.
This should only be called after the first page has been returned.
.. versionadded:: 2.0.0'

def start_fetching_next_page(self):

    if (not self._paging_state):
        raise QueryExhausted()
    self._make_query_plan()
    self.message.paging_state = self._paging_state
    self._event.clear()
    self._final_result = _NOT_SET
    self._final_exception = None
    self._start_timer()
    self.send_request()
