docs: static void checkInternalName(final String name, final int start,
              final int end, final String msg) {
          int max = end == -1 ? name.length() : end;
          try {
              int begin = start;
              int slash;
              do {
                  slash = name.indexOf('/', begin + 1);
                  if (slash == -1 || slash > max) {
                      slash = max;
                  }
                  checkIdentifier(name, begin, slash, null);
                  begin = slash + 1;
              } while (slash != max);
          } catch (IllegalArgumentException unused) {
              throw new IllegalArgumentException(
                      "Invalid "
                              + msg
                              + " (must be a fully qualified class name in internal form): "
                              + name);
          }
      }