@Contract(pure = true)
  public static @NotNull String join(String @NotNull ... strings) {
    if (strings.length == 0) return "";
    if (strings.length == 1) return strings[0];

    final StringBuilder builder = new StringBuilder();
    for (String string : strings) {
      builder.append(string);
    }
    return builder.toString();
  }
@Contract(pure = true)
  public static @NotNull String join(String @NotNull ... strings)