def test_negative_4(self):
        """
        More than two inputs to the stack op -- can't be transformed.
        """

        @mb.program(
            input_specs=[
                mb.TensorSpec(shape=(1, 5, 3, 4)),
                mb.TensorSpec(shape=(1, 5, 3, 4)),
                mb.TensorSpec(shape=(1, 5, 3, 4)),
            ]
        )
        def prog(x1, x2, x3):
            a = mb.stack(values=[x1, x2, x3], axis=1)
            a = mb.reshape(x=a, shape=[-1, 15, 4, 3])
            return a

        prev_prog, prev_block, block = apply_pass_and_basic_check(
            prog, "common::replace_stack_reshape"
        )

        self.assertEqual(get_op_types_in_program(prev_prog), ["stack", "reshape"])
        self.assertEqual(get_op_types_in_program(prog), ["stack", "reshape"])

        More than two inputs to the stack op -- can't be transformed.
        
coremltools/converters/mil/mil/passes/tests/test_passes.py