text: public virtual Antlr4.Runtime.Misc.IntervalSet Complement(IIntSet vocabulary){if (vocabulary == null || vocabulary.IsNil){return null;}Antlr4.Runtime.Misc.IntervalSet vocabularyIS;if (vocabulary is Antlr4.Runtime.Misc.IntervalSet){vocabularyIS = (Antlr4.Runtime.Misc.IntervalSet)vocabulary;}else{vocabularyIS = new Antlr4.Runtime.Misc.IntervalSet();vocabularyIS.AddAll(vocabulary);}return vocabularyIS.Subtract(this);}