GuiStateElement.State.getItem(HumanEntity)
GuiStorageElement.getPlaceValidator()
GuiStorageElement.getStorageItem(HumanEntity, int)
GuiStorageElement.setPlaceValidator(Function)
GuiStorageElement.setStorageItem(HumanEntity, int, ItemStack)
GuiStorageElement.validateItemPlace(int, ItemStack)
InventoryGui.setItemText(HumanEntity, ItemStack, String...)