spiceJ/real-time/src/main/java/at/borkowski/spicej/rt/RealTimeTickSource.java
@Override
   public void removeListener(TickListener listener) {
      super.removeListener(listener);

      if (listeners.isEmpty() && !keepAlive)
         stop();
   }
@Override
   public void removeListener(TickListener listener) {
      super.removeListener(listener);

      if (listeners.isEmpty() && !keepAlive)
         stop();
   }
If the last tick listener has been removed from this source, it shuts
itself down via {@link #stop()}, if it's not set to keepAlive mode using
{@link #setKeepAlive(boolean)}.