Upgrader_GUI:
    type: inventory
    inventory: CHEST
    title: Upgrade station
    size: 45
    gui: true
    slots:
    - [] [] [] [] [] [] [] [] []
    - [] [] [] [] [] [] [] [] []
    - [] [] [] [] [] [] [upgrade_button] [] []
    - [] [] [] [] [] [] [] [] []
    - [] [] [] [] [] [] [] [] []
# buttons

upgrade_button:
    type: item
    material: anvil
    display name: <&2>Upgrade
    lore:
    - <&7>Click to upgrade.

uncancel_inventory_world:
    type: world
    debug: true
    events:
        on player clicks in Upgrader_GUI slot:21 bukkit_priority:HIGHEST:
        - announce "the click do things - click"
        - determine cancelled:false