Antlr3.Tool.ErrorManager.GrammarError C# (CSharp) Method

        public static void GrammarError( int msgID,
                                        Grammar g,
                                        IToken token )
        {
            GrammarError( msgID, g, token, null, null );
        }

 public virtual string SetOption(IDictionary <string, object> options, HashSet <string> legalOptions, Grammar grammar, string key, object value)
 {
     if (!legalOptions.Contains(key))
     {
         ErrorManager.GrammarError(ErrorManager.MSG_ILLEGAL_OPTION,
                                   grammar,
                                   Token,
                                   key);
         return(null);
     }
     if (value is string)
     {
         string vs = (string)value;
         if (vs[0] == '"')
         {
             value = vs.Substring(1, vs.Length - 2);   // strip quotes
         }
     }
     if (key.Equals("k"))
     {
         grammar.numberOfManualLookaheadOptions++;
     }
     if (key == "backtrack" && value.ToString() == "true")
     {
         grammar.composite.RootGrammar.atLeastOneBacktrackOption = true;
     }
     options[key] = value;
     return(key);
 }