docs: private Map<String, ParseTreeNode> getHelperTokens() throws TreeException {
  	Map<String, ParseTreeNode> helpers = new HashMap<String, ParseTreeNode>();
  	ParseTreeNode helperTree = parserTree.getChild("Helper");
  	ParseTreeNode helperDefinitions = helperTree.getChild("HelperDefinitions");
  	for (ParseTreeNode helperDefinition : helperDefinitions
  		.getChildren("HelperDefinition")) {
  	    String identifier = helperDefinition.getChild("IDENTIFIER")
  		    .getText();
  	    helpers.put(identifier, helperDefinition);
  	}
  	return helpers;
      }