docs: def call_orig(self, *args, **kwargs):
          '''
          Calls the original function.
          '''
          if hasattr(self._obj, '__self__') and \
                  inspect.isclass(self._obj.__self__) and \
                  self._obj.__self__ is self._instance:
              return self._obj.__func__(self._instance, *args, **kwargs)
          elif hasattr(self._obj, 'im_self') and \
                  inspect.isclass(self._obj.im_self) and \
                  self._obj.im_self is self._instance:
              return self._obj.im_func(self._instance, *args, **kwargs)
          else:
              return self._obj(*args, **kwargs)