aggregation() {
    const aggregation = this._aggregation();
    if (aggregation) {
      return aggregation.aggregation();
    }
    return null;
  }
/**
   * Underlying aggregation, with aggregation-options removed
   */
Underlying aggregation, with aggregation-options removed
Underlying aggregation with aggregation - options removed
aggregation() {
    const aggregation = this._aggregation();
    if (aggregation) {
      return aggregation.aggregation();
    }
    return null;
  }
aggregation ( ) { const aggregation = this . _aggregation ( ) ; if ( aggregation ) { return aggregation . aggregation ( ) ; } return null ; }
Underlying aggregation, with aggregation-options removed
Underlying aggregation with aggregation - options removed