'Record a visit to this subreddit in the activity service.
This is used to show "here now" numbers. Multiple contexts allow us
to bucket different kinds of visitors (logged-in vs. logged-out etc.)
:param str context: The category of visitor. Must be one of
Subreddit.activity_contexts.
:param str visitor_id: A unique identifier for this visitor within the
given context.'

def record_visitor_activity(self, context, visitor_id):

    assert (context in self.activity_contexts)
    assert (self.activity_contexts == ('logged_in',))
    if (not c.activity_service):
        return
    try:
        c.activity_service.record_activity(self._fullname, visitor_id)
    except (TApplicationException, TProtocolException, TTransportException):
        pass
