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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def clear_inputhook(self, app=None):
 """Set PyOS_InputHook to NULL and return the previous one. Parameters app : optional, ignored This parameter is allowed only so that clear_inputhook() can be called with a similar interface as all the ``enable_*`` methods. But the actual value of the parameter is ignored. This uniform interface makes it easier to have user-level entry points in the main IPython app like :meth:`enable_gui`."""

        pyos_inputhook_ptr = self.get_pyos_inputhook()
        original = self.get_pyos_inputhook_as_func()
        pyos_inputhook_ptr.value = ctypes.c_void_p(None).value
        allow_CTRL_C()
        self._reset()
        return original