class DescriptionFormatter {

  private static final DescriptionFormatter INSTANCE = new DescriptionFormatter();

  /**
   * Returns the singleton instance of this class.
   * @return the singleton instance of this class.
   */
  public static DescriptionFormatter instance() {
    return INSTANCE;
  }

  @VisibleForTesting
  DescriptionFormatter() {}

  /**
   * Formats the given <code>{@link Description}</code> by surrounding its text value with square brackets and adding a space at
   * the end.
   * @param d the description to format. It can be {@code null}.
   * @return the formatted description, or an empty {@code String} if the {@code Description} is {@code null}.
   */
  public String format(Description d) {<FILL_FUNCTION_BODY>}

}

    String s = (d != null) ? d.value() : null;
    if (isNullOrEmpty(s)) return "";
    return String.format("[%s] ", s);
  
<no_super_class>