var ex = new Grouper(
        GroupOperator.OR,
        new Grouper (
                GroupOperator.AND,
                new Comparator("x", CompareOperator.EQUALS, 5),
                new Comparator("y", CompareOperator.BETWEEN, 10, 20)
        ),
        new Grouper(
                GroupOperator.AND,
                new Comparator("x", CompareOperator.GREATER_EQUALS, 50),
                new Comparator("z", CompareOperator.BETWEEN, 30, 70)
        ),
        new Grouper(
                GroupOperator.AND,
                new Comparator("name", CompareOperator.ISNULL),
                new Comparator("surname", CompareOperator.LIKE, "h%")
        )
);