Give enchant at death

var REGISTRY = Java.type('net.minecraftforge.fml.common.registry.ForgeRegistries');

function getAllEnchants() {
    var ENCHANTS = REGISTRY.ENCHANTMENTS.getValues();
    var allEnchants = [];
    for (var i in ENCHANTS) {
        var ench = ENCHANTS[i];
        var ename = REGISTRY.ENCHANTMENTS.getKey(ench);
        var eid = REGISTRY.ENCHANTMENTS.getID(ench);
        allEnchants.push({
            'name': ename.toString(),
            'id': eid
        });
    }

    return allEnchants;
}

var bookChance = 100; //% chance to get a book at all

function died(e) {
    if(e.source) {
        if(e.source.getType() == 1) {
            var giveBookChance = Math.random() * 100;

            if(giveBookChance < bookChance) {
                var enchants = getAllEnchants();
                var enchant = enchants[Math.round(Math.random() * (enchants.length - 1))];
                var item = e.npc.world.createItem('minecraft:enchanted_book', 0, 1);

                var itemNbt = item.getNbt();
                var enchantNbt = e.API.stringToNbt('{lvl:1s,id:'+enchant.id.toString()+'s}');
                itemNbt.setList('StoredEnchantments', [enchantNbt]); //Changing NBT, immediatly changes item

                e.source.giveItem(item);
            }
        }
    }
}