FurnaceBlockEntity
Currently burning fuel (appears in slot 1) total time in ticks (e.g. coal burns in 1600 ticks) before burning completed.
Counter to , when them equals furnace unlit.
Currently smelting item (appears in slot 0) progress, result will be presented in slot with index 2.
Accumulated experience, it will be dropped when result taken or furnace digged.
Amount of item in slot.
Dealed damage, when it comes to item will be broken.
Typed identifier, such as "minecraft:stick".
Indexed slot, required in containers with more than one slots.
Picked up by entity, denies despawn it naturally.
Block Entity will be saved without instantiating new one when transporting (via pistons, commands, etc.).