code: def getVariantId(self, gaVariant):
          
          md5 = self.hashVariant(gaVariant)
          compoundId = datamodel.VariantCompoundId(
              self.getCompoundId(), gaVariant.reference_name,
              str(gaVariant.start), md5)
          return str(compoundId)
docs: Returns an ID string suitable for the specified GA Variant
          object in this variant set.