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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 release_references(self, keys):
 """Non-recursively indicate that an iterable of _ReferenceKey no longer exist. Unknown keys are ignored. :param Iterable[_ReferenceKey] keys: The keys to drop. """

        keys = set(self.referenced_by) & set(keys)
        for key in keys:
            self.referenced_by.pop(key)