public override IAggregateFluent <AggregateBucketResult <TValue> > Bucket <TValue>(
     AggregateExpressionDefinition <TResult, TValue> groupBy,
     IEnumerable <TValue> boundaries,
     AggregateBucketOptions <TValue> options = null)
 {
     return(WithPipeline(_pipeline.Bucket(groupBy, boundaries, options)));
 }