public static <T> CollectionExpression<Collection<T>, T> collectionOperation(Class<T> elementType, Operator operator,
                                                                  Expression<?>... args) {
        return new CollectionOperation<T>(elementType, operator, args);
    }
Create a new Collection operation expression

@param elementType element type
@param operator operator
@param args operation arguments
@param <T> type of expression
@return operation expression
querydsl-core/src/main/java/com/querydsl/core/types/dsl/Expressions.java