code: private ItemStack handleShiftClick(MalisisInventory inventory, MalisisSlot slot)
  	{
  		ItemStack itemStack = transferSlotOutOfInventory(inventory, slot);
  
  		//replace what's left of the item back into the slot
  		slot.setItemStack(itemStack);
  		slot.onSlotChanged();
  		return itemStack;
  	}
docs: Handles shift clicking a slot.
  
  @param inventoryId the inventory id
  @param slot the slot
  @return the item stack