docs: @Override
      protected String badIdentifier(String expected) {
          error(expected);
  
          final String id = "@" + (nextId++);
          if (!peekPunctuation()) {
              final Token token = getNextToken();
              return "BAD_IDENTIFIER" + "_" + friendlyName(token) + id;
          } else {
              return "NO_IDENTIFIER" + id;
          }
      }