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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 runGetFeature(self, id_):
 """ Returns JSON string of the feature object corresponding to the feature compoundID passed in. """

        compoundId = datamodel.FeatureCompoundId.parse(id_)
        dataset = self.getDataRepository().getDataset(compoundId.dataset_id)
        featureSet = dataset.getFeatureSet(compoundId.feature_set_id)
        gaFeature = featureSet.getFeature(compoundId)
        jsonString = protocol.toJson(gaFeature)
        return jsonString