<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def find(self, *index):
 """ Searches the current entity for an instance with the specified index. Returns: The wanted instance if found, otherwise it returns `None`. """

        assert self.wrapFunction is not None
        if len(index) == 1 and isinstance(index[0], (tuple, list)):
            index = index[0]
        it = self._impl.find(Tuple(index)._impl)
        if it == self._impl.end():
            return None
        else:
            return self.wrapFunction(it)