code: public static @NotNull String format(@Nullable Description description, @NotNull String message) {
      checkNotNull(message);
      String s = valueOf(description);
      return format(s) + message;
    }
docs: Returns the given message formatted as follows:
  <pre>
  [description] message.
  </pre>
  
  @param description the description of the actual value in the failed assertion. It can be {@code null}.
  @param message     the message to format.
  @return the formatted message.
  @throws NullPointerException if the given message is {@code null}.
  @since 1.2