'Retrieve events and pagination tokens around a given event in a
room.
Args:
room_id (str)
event_id (str)
before_limit (int)
after_limit (int)
Returns:
dict'

@defer.inlineCallbacks
def get_events_around(self, room_id, event_id, before_limit, after_limit):

    results = (yield self.runInteraction('get_events_around', self._get_events_around_txn, room_id, event_id, before_limit, after_limit))
    events_before = (yield self._get_events([e for e in results['before']['event_ids']], get_prev_content=True))
    events_after = (yield self._get_events([e for e in results['after']['event_ids']], get_prev_content=True))
    defer.returnValue({'events_before': events_before, 'events_after': events_after, 'start': results['before']['token'], 'end': results['after']['token']})
