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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_if_deleted(self, addresses):
 """Returns a list of addresses that have been deleted, or None if it hasn't been deleted. Args: addresses (list of str):
 The addresses to check if deleted. Returns: (list of str):
 The addresses, if deleted, or None. """


        with self._lock:
            results = []
            for add in addresses:
                results.append(self._get_if_deleted(add))
            return results