@Override protected void invalidated() {
                    stopTask(periodicTickTask);
                    if (isAnimated()) return;
                    scheduleTickTask();
                }
Defines if the second hand of the clock should move in
discrete steps of 1 second. Otherwise it will move continuously like
in an automatic clock.
@param DISCRETE
src/main/java/eu/hansolo/tilesfx/Tile.java