}

  /**
   * A reference implementation for {@code tryParse} that just catches the exception from {@link
   * Double#valueOf}.
   */
  private static @Nullable Double referenceTryParse(String input) {
    if (input.trim().length() < input.length()) {
      return null;
    }
    try {
      return Double.valueOf(input);
    } catch (NumberFormatException e) {
      return null;