def test_builder_eval_different_dtypes_error_out(self):
        """If the input to the concat op has different dtypes, it will error out."""
        with pytest.raises(
            ValueError,
            match="Tensors in 'values' of the concat op \(concat_0\) should share the same data type",
        ):

            @mb.program(
                input_specs=[
                    mb.TensorSpec(shape=(2, 3), dtype=types.fp32),
                    mb.TensorSpec(shape=(2, 3), dtype=types.int32),
                ]
            )
            def prog(x1, x2):
                return mb.concat(values=[x1, x2], axis=0)
If the input to the concat op has different dtypes, it will error out.
coremltools/converters/mil/mil/ops/tests/iOS14/test_tensor_operation.py