code: private Map < String, Object > getProps(int fieldIndex,
              XmlSchemaChoice xsdChoice, RootCompositeType compositeTypes) {
  
          String choiceTypeName = getComplexTypeName(xsdChoice);
          visit(xsdChoice, compositeTypes, choiceTypeName);
  
          Map < String, Object > props = new LinkedHashMap < String, Object >();
          props.put(FIELD_INDEX_PROP_NAME, fieldIndex);
          props.put(CHOICE_TYPE_PROP_NAME, true);
          props.put(CHOICE_TYPE_NAME_PROP_NAME, choiceTypeName);
          props.put(ALTERNATIVES_PROP_NAME, compositeTypes.choiceTypes.get(choiceTypeName));
  
          return props;
  
      }
docs: Retrieve the properties of a choice element.
  <p/>
  Use the opportunity to visit each of the choice's alternatives.
  
  @param fieldIndex the order of the choice in the parent complex type
  @param xsdChoice the choice element
  @param compositeTypes the lists of composite types being populated
  @return the choice's properties