def METHOD_NAME():
    with pytest.raises(exceptions.ValidationError):
        validation.check_instances("abc", str)
    with pytest.raises(exceptions.ValidationError):
        validation.check_instances(["abc", 123], str)
    with pytest.raises(exceptions.ValidationError):
        validation.check_instances(None, str)
    with pytest.raises(exceptions.ValidationError):
        validation.check_instances([None], str)
    with pytest.raises(exceptions.ValidationError):
        validation.check_instances(iter(["abc"]), str)