public final int yypop() {
      if (stack.size() == 0) {
          yyinitial();
          return YYINITIAL;
      }

      int state = stack.pop();

      if (stack.peek() == null) {
          yyinitial();
      } else {
          yybegin(stack.peek());
      }

      return state;
  }
public final int yypop()