code: private void setChoices(BigInteger multiChoice, JSchema schema) {
      JSType topType = (JSType)schema.getJMFType();
      if (topType instanceof JSVariant)
        setChoices(multiChoice, schema, (JSVariant)topType);
      else if (topType instanceof JSTuple)
        setChoices(
          multiChoice,
          topType.getMultiChoiceCount(),
          schema,
          ((JSTuple)topType).getDominatedVariants());
      else
        // If topType is JSRepeated, JSDynamic, JSEnum, or JSPrimitive there can be no unboxed
        // variants at top level.
        return;
    }
docs: multichoice code.