code: public static HarCustomFields createMessageHarCustomFields(int historyId, int historyType, String messageNote) {
          HarCustomFields customFields = new HarCustomFields();
          customFields.addCustomField(MESSAGE_ID_CUSTOM_FIELD, Integer.toString(historyId));
          customFields.addCustomField(MESSAGE_TYPE_CUSTOM_FIELD, Integer.toString(historyType));
          customFields.addCustomField(MESSAGE_NOTE_CUSTOM_FIELD, messageNote);
          return customFields;
      }
docs: Creates custom fields for the given data.
  
  @param historyId the history ID of the HTTP message.
  @param historyType the history type of the HTTP message.
  @param messageNote the note of the HTTP message.
  @return the {@code HarCustomFields}, never {@code null}.
  @since TODO add version
  @see #createHarEntry(int, int, HttpMessage)