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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 iter_instances(self):
 """Iterate over the stored objects Yields: wrkey: The two-tuple key used to store the object obj: The instance or function object """

        for wrkey in set(self.keys()):
            obj = self.get(wrkey)
            if obj is None:
                continue
            yield wrkey, obj