@NotNull
    @Override
    public String toString(@NotNull Character shortcut) {
      return shortcut == TAB_CHAR ? TAB :
             shortcut == ENTER_CHAR ? ENTER :
             shortcut == CUSTOM_CHAR ? CUSTOM :
             shortcut == NONE_CHAR ? NONE :
             SPACE;
    }
@NotNull
    @Override
    public String toString(@NotNull Character shortcut)