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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_set(self, addresses):
 """Returns the value set in this context, or None, for each address in addresses. Args: addresses (list of str):
 The addresses to return values for, if set within this context. Returns: (list):
 bytes set at the address or None """


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