Slot slot = (Slot) inventorySlots.get(machineIndex);
if (slot instanceof SlotRailcraft) {
SlotRailcraft slotRailcraft = (SlotRailcraft) slot;
if (slotRailcraft.isPhantom())
continue;
if (!slotRailcraft.canShift())
continue;
}
if (!slot.isItemValid(stackToShift))
continue;
if (shiftItemStack(stackToShift, machineIndex, machineIndex + 1))