docs: public synchronized void destroy()
  	{
  		if (state == DESTROYED)
  			return;
  		if (state != DISCONNECTED)
  			try {
  				tl.disconnect(this);
  			}
  			catch (final KNXLinkClosedException e) {
  				// we already should've been destroyed on catching this exception
  			}
  		setState(DESTROYED);
  		tl.destroyDestination(this);
  	}