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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 _delete_objects_not_in_list(self, cont, object_prefix=""):
 """ Finds all the objects in the specified container that are not present in the self._local_files list, and deletes them. """

        objnames = set(cont.get_object_names(prefix=object_prefix,
                full_listing=True))
        localnames = set(self._local_files)
        to_delete = list(objnames.difference(localnames))
        self._sync_summary["deleted"] += len(to_delete)
        # We don't need to wait around for this to complete. Store the thread
        # reference in case it is needed at some point.
        self._thread = self.bulk_delete(cont, to_delete, async_=True)