'Retrieve a single specified event.
Args:
user (synapse.types.UserID): The user requesting the event
event_id (str): The event ID to obtain.
Returns:
dict: An event, or None if there is no event matching this ID.
Raises:
SynapseError if there was a problem retrieving this event, or
AuthError if the user does not have the rights to inspect this
event.'

@defer.inlineCallbacks
def get_event(self, user, event_id):

    event = (yield self.store.get_event(event_id))
    if (not event):
        defer.returnValue(None)
        return
    if hasattr(event, 'room_id'):
        (yield self.auth.check_joined_room(event.room_id, user.to_string()))
    defer.returnValue(event)
