`test_functools` includes a test to check that `functools.singledispatch` correctly wraps the attributes of the target function. However, there is no equivalent test for `functools.singledispatchmethod`. There should be, as this is done separately in the `__get__` method of `functools.singledispatchmethod`; it is a different mechanism to `functools.singledispatch`.

Additionally, `test_abstractmethod_register` tests that the return value of `singledispatchmethod.__get__` wraps the target function's `__isabstractmethod__` attribute. However, the `__isabstractmethod__` property of the `singledispatchmethod` class is untested.