def test_create_program_function_name(self):
        """
        If ``function_name`` is not provide, mb.program creates function with name "main" by default.
        """
        # defaults to "main"
        @mb.program(input_specs=[mb.TensorSpec(shape=(2, 4))])
        def prog(x0):
            return x0

        assert len(prog.functions) == 1
        assert "main" in prog.functions

        # user can also provide function_name
        @mb.program(input_specs=[mb.TensorSpec(shape=(2, 4))], function_name="good_function")
        def prog(x0):
            return x0

        assert len(prog.functions) == 1
        assert "good_function" in prog.functions

        If ``function_name`` is not provide, mb.program creates function with name "main" by default.
        
coremltools/converters/mil/mil/tests/test_programs.py