docs: private void convertProductionGroup(ParseTreeNode productionDefinition)
  	    throws GrammarException, TreeException {
  	String productionName = productionDefinition.getChild("IDENTIFIER")
  		.getText();
  	ParseTreeNode productionConstructions = productionDefinition
  		.getChild("ProductionConstructions");
  	convertSingleProductions(productionName, productionConstructions);
      }