code: func (r *BulkUpdateRequest) DocAsUpsert(docAsUpsert bool) *BulkUpdateRequest {
  	r.docAsUpsert = &docAsUpsert
  	r.source = nil
  	return r
  }
docs: // DocAsUpsert indicates whether the contents of Doc should be used as
  // the Upsert value.
  //
  // See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/docs-update.html#_literal_doc_as_upsert_literal
  // for details.