@Contract(pure = true)
  public static @NotNull String capitalize(@NotNull String s) {
    if (s.isEmpty()) return s;
    if (s.length() == 1) return toUpperCase(s);
    if (Character.isUpperCase(s.charAt(0))) return s;
    return toUpperCase(s.charAt(0)) + s.substring(1);
  }
@Contract(pure = true)
  public static @NotNull String capitalize(@NotNull String s)