#482: Add a DragonBattle API to manipulate respawn phases etc

By: Parker Hawke <hawkeboyz2@hotmail.com>

paper-api/src/main/java/org/bukkit/World.java

@@ -10,6 +10,7 @@ import java.util.function.Predicate;
 import org.bukkit.block.Biome;
 import org.bukkit.block.Block;
 import org.bukkit.block.data.BlockData;
+import org.bukkit.boss.DragonBattle;
 import org.bukkit.entity.AbstractArrow;
 import org.bukkit.entity.Arrow;
 import org.bukkit.entity.Entity;
@@ -2241,6 +2242,21 @@ public interface World extends PluginMessageRecipient, Metadatable {
     @NotNull
     public List<Raid> getRaids();
 
+    /**
+     * Get the {@link DragonBattle} associated with this world.
+     *
+     * If this world's environment is not {@link Environment#THE_END}, null will
+     * be returned.
+     * <p>
+     * If an end world, a dragon battle instance will be returned regardless of
+     * whether or not a dragon is present in the world or a fight sequence has
+     * been activated. The dragon battle instance acts as a state holder.
+     *
+     * @return the dragon battle instance
+     */
+    @Nullable
+    public DragonBattle getEnderDragonBattle();
+
     /**
      * Represents various map environment types that a world may be
      */