indexOfAggregationResult
internal fun <Value : Return & Any, Return> Aggregator<Value, Return>.indexOfAggregationResult(values: Sequence<Value?>, valueType: ValueType): Int
internal fun <Value : Return & Any, Return> Aggregator<Value, Return>.indexOfAggregationResult(values: Sequence<Value?>, valueType: KType): Int
Gives the index of the aggregation result in the input values, if it applies. This is used for aggregators with an AggregatorAggregationHandler where Value== Return, and where the result exists in the input.
Like for SelectingAggregationHandler.
Defaults to -1.
If valueType is unknown, see calculateValueType