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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 representation of this FeatureSet as the corresponding ProtocolElement. """

        gaFeatureSet = protocol.FeatureSet()
        gaFeatureSet.id = self.getId()
        gaFeatureSet.dataset_id = self.getParentContainer().getId()
        gaFeatureSet.reference_set_id = pb.string(self._referenceSet.getId())
        gaFeatureSet.name = self._name
        gaFeatureSet.source_uri = self._sourceUri
        attributes = self.getAttributes()
        for key in attributes:
            gaFeatureSet.attributes.attr[key] \
                .values.extend(protocol.encodeValue(attributes[key]))
        return gaFeatureSet