'Returns True if event_id1 is after event_id2 in the stream'

@defer.inlineCallbacks
def is_event_after(self, event_id1, event_id2):

    (to_1, so_1) = (yield self._get_event_ordering(event_id1))
    (to_2, so_2) = (yield self._get_event_ordering(event_id2))
    defer.returnValue(((to_1, so_1) > (to_2, so_2)))
