public Set<OrderStatus> possibleTransitions(OrderStatus from_status, DeliveryType for_deliveryType)
	{
		Set<OrderStatus> ret = new HashSet<>();
		if(from_status != null)
			switch(from_status)
			{
				case PROCESSING:
					ret.addAll(Arrays.asList(DELIVERY, CANCELLED));
					break;
				case DELIVERY:
					if(for_deliveryType == DeliveryType.PICKUP)
						ret.addAll(Arrays.asList(PICKUP, CANCELLED));
					else if(for_deliveryType == DeliveryType.DELIVERY)
						ret.addAll(Arrays.asList(DELIVERED, CANCELLED));
					break;
				case PICKUP:
					ret.addAll(Arrays.asList(DELIVERED, CANCELLED));
					break;
				default:
					break;
			}

		return ret;
	}