docs: @Override
  	protected void checkPrimitiveValidity() {
  		BusPrimitiveInvalidity invalidityReason = null;
  		if (this.position == null) {
  			invalidityReason =
  					new BusPrimitiveInvalidity(
  							BusPrimitiveInvalidityType.NO_STOP_POSITION,
  							null);
  		} else {
  			final BusNetwork busNetwork = getBusNetwork();
  			if (busNetwork == null) {
  				invalidityReason = new BusPrimitiveInvalidity(
  						BusPrimitiveInvalidityType.STOP_NOT_IN_NETWORK,
  						null);
  			} else {
  				final RoadNetwork roadNetwork = busNetwork.getRoadNetwork();
  				if (roadNetwork == null) {
  					invalidityReason = new BusPrimitiveInvalidity(
  							BusPrimitiveInvalidityType.STOP_NOT_IN_NETWORK,
  							null);
  				} else {
  					final Rectangle2d bounds = roadNetwork.getBoundingBox();
  					if (bounds == null || !bounds.contains(this.position.getPoint())) {
  						invalidityReason = new BusPrimitiveInvalidity(
  								BusPrimitiveInvalidityType.OUTSIDE_MAP_BOUNDS,
  								bounds == null ? null : bounds.toString());
  					}
  				}
  			}
  		}
  		setPrimitiveValidity(invalidityReason);
  	}