private static INfa Character(RegexCharacter character)
 {
     var start = new NfaState();
     var end = new NfaState();
     var terminal = new CharacterTerminal(character.Value);
     var transition = new TerminalNfaTransition(
         terminal: terminal,
         target: end);
     start.AddTransistion(transition);
     return new Nfa(start, end);
 }
 private static INfa Character(RegexCharacterClassCharacter character, bool negate)
 {
     var start = new NfaState();
     var end = new NfaState();
     ITerminal terminal = new CharacterTerminal(character.Value);
     if (negate)
         terminal = new NegationTerminal(terminal);
     var transition = new TerminalNfaTransition(
         terminal: terminal,
         target: end);
     start.AddTransistion(transition);
     return new Nfa(start, end);
 }