code: def _InsertEvent(self, event, force_flush=False):
      
      if event:
        event_document = {'index': {
            '_index': self._index_name, '_type': self._document_type}}
        event_values = self._GetSanitizedEventValues(event)
  
        self._event_documents.append(event_document)
        self._event_documents.append(event_values)
        self._number_of_buffered_events += 1
  
      if force_flush or self._number_of_buffered_events > self._flush_interval:
        self._FlushEvents()
docs: Inserts an event.
  
      Events are buffered in the form of documents and inserted to Elasticsearch
      when either forced to flush or when the flush interval (threshold) has been
      reached.
  
      Args:
        event (EventObject): event.
        force_flush (bool): True if buffered event documents should be inserted
            into Elasticsearch.