protected static FactoryExpression<Tuple> withoutGroupExpressions(final FactoryExpression<Tuple> expr) {
        List<Expression<?>> args = new ArrayList<Expression<?>>(expr.getArgs().size());
        for (Expression<?> arg : expr.getArgs()) {
            if (arg instanceof GroupExpression) {
                args.add(((GroupExpression) arg).getExpression());
            } else {
                args.add(arg);
            }
        }
        return new FactoryExpressionAdapter<Tuple>(expr, args);
    }
Base class for GroupBy result transformers

@author tiwe

@param <K>
@param <T>
querydsl-core/src/main/java/com/querydsl/core/group/AbstractGroupByTransformer.java