@SuppressLint("WrongConstant")
        private void showUndoToast(final String resultMessage) {
            if (StringUtils.isNotEmpty(resultMessage)) {
                Snackbar.make(context.findViewById(android.R.id.content), resultMessage, UNDO_DURATION_MILLISEC)
                        .setAction(context.getString(R.string.undo), this)
                        .setAnchorView(context.findViewById(R.id.activity_navigationBar))
                        .show();
            }
        }
Message to be shown as toast when the command finished. Can be {@code null}, if the operation does not support
undo.
main/src/main/java/cgeo/geocaching/command/AbstractCommand.java