'Requests all state for a given room from the given server at the
given event. Returns the state\'s event_id\'s
Args:
destination (str): The host name of the remote home server we want
to get the state from.
context (str): The name of the context we want the state of
event_id (str): The event we want the context at.
Returns:
Deferred: Results in a dict received from the remote homeserver.'

@log_function
def get_room_state_ids(self, destination, room_id, event_id):

    logger.debug('get_room_state_ids    dest=%s,    room=%s', destination, room_id)
    path = (PREFIX + ('/state_ids/%s/' % room_id))
    return self.client.get_json(destination, path=path, args={'event_id': event_id})
