private boolean checkConstraints() {
		//HACK: prevent inserts/updates during objectOnDelete
		if (aboutToDelete)
			return false;

		if (this.power < 0)
			return false;
		if (this.fuelType == null) 
			return false;
		if (this.model == null)
			return false;
		if (this.priceClass == null)
			return false;
		return true;
	}