code: def PushEvent(self, event):
      
      macb_group_identifier, content_identifier = self._GetEventIdentifiers(event)
  
      # We can ignore the timestamp here because the psort engine only stores
      # events with the same timestamp in the event heap.
      heap_values = (macb_group_identifier or '', content_identifier, event)
      heapq.heappush(self._heap, heap_values)
docs: Pushes an event onto the heap.
  
      Args:
        event (EventObject): event.