docs: private TokenDefinition getTokenDefinition(ParseTreeNode tokenDefinition,
  	    Map<String, ParseTreeNode> helpers, Map<String, ParseTreeNode> tokens)
  	    throws GrammarException, TreeException {
  	String tokenName = tokenDefinition.getChild("IDENTIFIER").getText();
  	String pattern = createTokenDefinitionPattern(tokenDefinition, helpers,
  		tokens);
  	boolean ignoreCase = Boolean.valueOf((String) options
  		.get("grammar.ignore-case"));
  	if (tokenVisibility.get(tokenName) != null) {
  	    return new TokenDefinition(tokenName, pattern,
  		    tokenVisibility.get(tokenName), ignoreCase);
  	} else {
  	    return new TokenDefinition(tokenName, pattern, ignoreCase);
  	}
      }