code: public void addClassElements(final UIClassification _uiclass,
                                   final Map<UUID, String> _instanceKeys)
          throws EFapsException
      {
          this.elements.addAll(getClassElements(_uiclass, _instanceKeys));
      }
docs: Method that adds the classification forms as elements to the form by
  walking down the tree.
  
  @param _uiclass the classification to be added
  @param _instanceKeys map from uuid to instance keys
  @throws EFapsException on error