def test_add():
bset = BabyIntegerSet([1, 3, 5, 3])
bset.add(3)
assert len(bset.dump_data()) == 3
def test_add_exception():
bset = BabyIntegerSet()
with pytest.raises(UnsupportedTypeError) as exeinfo:
bset.add('9')
assert 'not a valid integer' in str(exeinfo)