Code Generation for TypedKeys (#9233)

Currently includes generated key holder classes for types
used in the Registry Modification API

patches/api/0172-Entity-getEntitySpawnReason.patch

@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Sun, 24 Mar 2019 00:21:23 -0400
+Subject: [PATCH] Entity#getEntitySpawnReason
+
+Allows you to return the SpawnReason for why an Entity Spawned
+
+Pre existing entities will return NATURAL if it was a non
+persistenting Living Entity, SPAWNER for spawners,
+or DEFAULT since data was not stored.
+
+Co-authored-by: Aurora <aurora@relanet.eu>
+
+diff --git a/src/main/java/org/bukkit/entity/Entity.java b/src/main/java/org/bukkit/entity/Entity.java
+index 711d95bfafac0d415895023bdaac4059395667ab..20a83a2fa9f3d65837fffb027b1f8f1e76957770 100644
+--- a/src/main/java/org/bukkit/entity/Entity.java
++++ b/src/main/java/org/bukkit/entity/Entity.java
+@@ -795,5 +795,11 @@ public interface Entity extends Metadatable, CommandSender, Nameable, Persistent
+         // TODO remove impl here
+         return getLocation().getChunk();
+     }
++
++    /**
++     * @return The {@link org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason} that initially spawned this entity. <!-- Paper - added "initially" to clarify that the SpawnReason doesn't change after the Entity was initially spawned" -->
++     */
++    @NotNull
++    org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason getEntitySpawnReason();
+     // Paper end
+ }