public @interface AggregatorType
The aggregator type annotation describes the type constraints for the selected aggregator. In version 1.4, two kinds of
aggregators are supported:
An aggregator that does not consider any parameter value from the call (count), just calculates the
number of matches. This is represented by a single Void and a single corresponding return type.
An aggregator that considers a single parameter from the call, and executes some aggregate operations over it.
Such an aggregate operation can be defined over multiple types, where each possible parameter type has a corresponding return type declared.
Important! The parameterTypes and returnTypes arrays must have