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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def callback(self, timestamp, event_type, payload):
 """Callback method for processing events in notification queue. :param timestamp: time the message is received. :param event_type: event type in the notification queue such as identity.project.created, identity.project.deleted. :param payload: Contains information of an event """

        try:
            data = (event_type, payload)
            LOG.debug('RX NOTIFICATION ==>\nevent_type: %(event)s, '
                      'payload: %(payload)s\n', (
                          {'event': event_type, 'payload': payload}))
            if 'create' in event_type:
                pri = self._create_pri
            elif 'delete' in event_type:
                pri = self._delete_pri
            elif 'update' in event_type:
                pri = self._update_pri
            else:
                pri = self._delete_pri
            self._pq.put((pri, timestamp, data))

        except Exception as exc:
            LOG.exception('Error: %(err)s for event %(event)s',
                          {'err': str(exc), 'event': event_type})