public static net.minecraft.server.v1_13_R2.ItemStack shiftClick(Container nmsContainer, EntityHuman nmsPlayer, int slotNumber) {
        net.minecraft.server.v1_13_R2.ItemStack result = net.minecraft.server.v1_13_R2.ItemStack.a; //AIR
        Slot slot = nmsContainer.slots.get(slotNumber);
        if (slot != null && slot.hasItem()) {
            net.minecraft.server.v1_13_R2.ItemStack currentItem = slot.getItem();
            result = currentItem.cloneItemStack();
            EnumItemSlot enumitemslot = EntityInsentient.e(result);
            if (slotNumber == 0) {
                if (cantStoreStack(nmsContainer, currentItem, 9, 45, true))
                    return null;
                slot.a(currentItem, result);
            } else if (slotNumber < 5) {
                if (cantStoreStack(nmsContainer, currentItem, 9, 45, false))
                    return null;
            } else if (slotNumber < 9) {
                if (cantStoreStack(nmsContainer, currentItem, 9, 45, false))
                    return null;
            } else if (enumitemslot.a() == EnumItemSlot.Function.ARMOR && !nmsContainer.slots.get(8 - enumitemslot.b()).hasItem()) {
                if (cantStoreStack(nmsContainer, currentItem, 8 - enumitemslot.b(), 8 - enumitemslot.b() + 1, false))
                    return null;
            } else if (enumitemslot == EnumItemSlot.OFFHAND && !nmsContainer.slots.get(45).hasItem()) {
                if (cantStoreStack(nmsContainer, currentItem, 45, 46, false))
                    return null;
            } else if (slotNumber < 36) {
                if (cantStoreStack(nmsContainer, currentItem, 36, 45, false))
                    return null;
            } else if (slotNumber < 45) {
                if (cantStoreStack(nmsContainer, currentItem, 9, 36, false))
                    return null;
            } else if (cantStoreStack(nmsContainer, currentItem, 9, 45, false))
                return null;
            if (currentItem.isEmpty())
                slot.set(net.minecraft.server.v1_13_R2.ItemStack.a); //AIR
            else
                slot.inventory.update();
            if (currentItem.getCount() == result.getCount())
                return null;
            slot.inventory.update();
            if (slotNumber == 0)
                nmsPlayer.drop(currentItem, false);
        }
        return result;
    }

    private static boolean cantStoreStack(Container nmsContainer, net.minecraft.server.v1_13_R2.ItemStack targetStack, int firstSlot, int lastSlot, boolean inverse) {
        boolean result = false;
        int slotNumber = firstSlot;
        if (inverse)
            slotNumber = lastSlot - 1;
        Slot slot;
        net.minecraft.server.v1_13_R2.ItemStack currentStack;
        if (targetStack.isStackable()) {
            while (!targetStack.isEmpty()) {
                if (inverse) {
                    if (slotNumber < firstSlot)
                        break;
                } else if (slotNumber >= lastSlot)
                    break;
                slot = nmsContainer.slots.get(slotNumber);
                currentStack = slot.getItem();
                if (!currentStack.isEmpty() && (targetStack.getItem() == currentStack.getItem() && net.minecraft.server.v1_13_R2.ItemStack.equals(targetStack, currentStack))) {
                    int count = currentStack.getCount() + targetStack.getCount();
                    if (count <= targetStack.getMaxStackSize()) {
                        targetStack.setCount(0);
                        currentStack.setCount(count);
                        slot.inventory.update();
                        result = true;
                    } else if (currentStack.getCount() < targetStack.getMaxStackSize()) {
                        targetStack.subtract(targetStack.getMaxStackSize() - currentStack.getCount());
                        currentStack.setCount(targetStack.getMaxStackSize());
                        slot.inventory.update();
                        result = true;
                    }
                }
                if (inverse)
                    --slotNumber;
                else
                    ++slotNumber;
            }
        }
        if (!targetStack.isEmpty()) {
            if (inverse)
                slotNumber = lastSlot - 1;
            else
                slotNumber = firstSlot;
            while (true) {
                if (inverse)
                    if (slotNumber < firstSlot)
                        break;
                else if (slotNumber >= lastSlot)
                    break;
                slot = nmsContainer.slots.get(slotNumber);
                currentStack = slot.getItem();
                if (currentStack.isEmpty() && slot.isAllowed(targetStack)) {
                    if (targetStack.getCount() > slot.getMaxStackSize())
                        slot.set(targetStack.cloneAndSubtract(slot.getMaxStackSize()));
                    else
                        slot.set(targetStack.cloneAndSubtract(targetStack.getCount()));
                    slot.inventory.update();
                    result = true;
                    break;
                }
                if (inverse)
                    --slotNumber;
                else
                    ++slotNumber;
            }
        }
        return !result;
    }