'Multi-output CustomClassifiers don\'t work because they use special
output allocation for string arrays.'

@parameter_space(dtype_=[categorical_dtype, int64_dtype], outputs_=[('a',), ('a', 'b')])
def test_reject_multi_output_classifiers(self, dtype_, outputs_):

    class SomeClassifier(CustomClassifier, ):
        dtype = dtype_
        window_length = 5
        inputs = [SomeDataSet.foo, SomeDataSet.bar]
        outputs = outputs_
        missing_value = dtype_.type('123')
    expected_error = 'SomeClassifier    does    not    support    custom    outputs,    but    received    custom    outputs={outputs}.'.format(outputs=outputs_)
    with self.assertRaises(ValueError) as e:
        SomeClassifier()
    self.assertEqual(str(e.exception), expected_error)
    with self.assertRaises(ValueError) as e:
        SomeClassifier()
    self.assertEqual(str(e.exception), expected_error)
