def METHOD_NAME():
    class Test(AbstractDalQueryParam):
        def get_dal_format(self, item):
            return str(item)
    # check test_obs behaves like a set but also holds the dal representation
    test_obs = Test()
    test_obs.add(1)
    assert 1 in test_obs
    assert test_obs.dal == ['1']
    test_obs.add(2)
    test_obs.add(3)
    assert len(test_obs) == 3
    assert test_obs.dal == ['1', '2', '3']
    assert {2, 3} < test_obs
    assert {1, 2, 3, 4} > test_obs
    test_obs.clear()
    assert len(test_obs) == 0
    assert len(test_obs.dal) == 0