YAML configuration hierarchy

Note the hierarchy when working with ItemStack in YAML. This is similar to how commands and permissions have nested values in the plugin.yml files. We can utilize a hierarchy within the config file to make it easier to use and understand.

We want to give items to two types of mobs, namely Zombie and Skeleton. Each type will have a unique armor and weapon. This means that we will need 10 different ItemStack classes. We can name them ZombieHolding, SkeletonHolding, ZombieHelmet, SkeletonHelmet, and so on. However, a hierarchy will be much more efficient. We will have a Zombie key and a Skeleton key. Within each zombie and skeleton, we will have a key for each item. The following is a sample of the hierarchy of the mob armor segment of the config file:

Zombie:
  holding:
    ==: org.bukkit.inventory.ItemStack
    type: STONE_SWORD
  helmet:
    ==: org.bukkit.inventory.ItemStack
    type: CHAINMAIL_HELMET

Skeleton:
  holding:
    ==: org.bukkit.inventory.ItemStack...