@SuppressWarnings("unchecked")
    protected V transform(Group group) {
        return (V) group;
    }
Provides aggregated results as a collection

@param <K> Key type
@param <V> Value type
@param <RES> Concrete collection type
@author Jan-Willem Gmelig Meyling
querydsl-core/src/main/java/com/querydsl/core/group/GroupByGenericCollection.java