code: def getCompoundIdForFeatureId(self, featureId):
          
          if featureId is not None and featureId != "":
              compoundId = datamodel.FeatureCompoundId(
                  self.getCompoundId(), str(featureId))
          else:
              compoundId = ""
          return str(compoundId)
docs: Returns server-style compound ID for an internal featureId.
  
          :param long featureId: id of feature in database
          :return: string representing ID for the specified GA4GH protocol
              Feature object in this FeatureSet.