docs: private Construction generateOptionalList(ParseTreeNode productionPart)
  	    throws TreeException, GrammarException {
  	String newIdentifier = createNewIdentifier(productionPart, "optlist");
  	Construction construction = createConstruction(productionPart);
  
  	Production production = new Production(newIdentifier);
  	production.addConstruction(new NonTerminal(newIdentifier));
  	production.addConstruction(construction);
  	production.setNode(false);
  	production.setStackingAllowed(false);
  	productions.add(production);
  
  	production = new Production(newIdentifier);
  	production.setNode(false);
  	production.setStackingAllowed(false);
  	productions.add(production);
  
  	return new NonTerminal(newIdentifier);
      }