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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 get_all_if_deleted(self):
 """Return all the addresses deleted in the context. Useful in the squash method. Returns: (dict of str to bytes):
 The addresses and bytes that have been deleted in the context. """


        with self._lock:
            results = {}
            for add, fut in self._state.items():
                if self._contains_and_deleted(add):
                    results[add] = fut.result()
            return results