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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 waiters(self, path=None):
 """Iterate over all waiters. This method will return the waiters in unspecified order including the future or callback object that will be invoked and a list containing the keys/value that are being matched. Yields: list, future or callable """


        context = self._waiters

        if path is None:
            path = []

        for key in path:
            context = context[key]

        if self._LEAF in context:
            for future in context[self._LEAF]:
                yield (path, future)

        for key in context:
            if key is self._LEAF:
                continue

            yield from self.waiters(path=path + [key])