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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 process_notifications(self, messages):
 """Process notifications."""

        for object_id, object_size, metadata_size in messages:
            if object_size > 0 and object_id in self._waiting_dict:
                linked_list = self._waiting_dict[object_id]
                self._complete_future(linked_list)