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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 toProtocolElement(self):
 """ Returns the GA4GH protocol representation of this ReadGroupSet. """

        readGroupSet = protocol.ReadGroupSet()
        readGroupSet.id = self.getId()
        readGroupSet.read_groups.extend(
            [readGroup.toProtocolElement()
             for readGroup in self.getReadGroups()]
        )
        readGroupSet.name = self.getLocalId()
        readGroupSet.dataset_id = self.getParentContainer().getId()
        readGroupSet.stats.CopyFrom(self.getStats())
        self.serializeAttributes(readGroupSet)
        return readGroupSet