| token | Name of the aggregator used when typing the query. This name is converted to lowercase when parsing the query to speed up the process. |
| aggregator | Aggregator function. Takes the results of the nested query, and returns an aggregate that contains any number of items. |
Adds a new nested query aggregator. An aggregator is an operation that can be applied on a nested query to aggregate the results of the nested query according to certain criteria.
<typeparam name="TNestedQueryData">The type of data returned by the nested query.</typeparam>