Added a few constructors to specify the instance directly

src/main/java/net/minestom/server/entity/Entity.java

@@ -344,6 +344,8 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer {
 
     /**
      * Updates the entity, called every tick.
+     * <p>
+     * Ignored if {@link #getInstance()} returns null.
      *
      * @param time the update time in milliseconds
      */

src/main/java/net/minestom/server/entity/EntityCreature.java

@@ -55,7 +55,7 @@ public abstract class EntityCreature extends LivingEntity {
     private final ReentrantLock pathLock = new ReentrantLock();
 
 
-    public EntityCreature(EntityType entityType, Position spawnPosition) {
+    public EntityCreature(@NotNull EntityType entityType, @NotNull Position spawnPosition) {
         super(entityType, spawnPosition);
 
         this.mainHandItem = ItemStack.getAirItem();
@@ -69,6 +69,14 @@ public abstract class EntityCreature extends LivingEntity {
         heal();
     }
 
+    public EntityCreature(@NotNull EntityType entityType, @NotNull Position spawnPosition, @Nullable Instance instance) {
+        this(entityType, spawnPosition);
+
+        if (instance != null) {
+            setInstance(instance);
+        }
+    }
+
     @Override
     public void update(long time) {
 

src/main/java/net/minestom/server/entity/ExperienceOrb.java

@@ -1,20 +1,31 @@
 package net.minestom.server.entity;
 
+import net.minestom.server.instance.Instance;
 import net.minestom.server.network.packet.server.play.SpawnExperienceOrbPacket;
 import net.minestom.server.network.player.PlayerConnection;
+import net.minestom.server.utils.Position;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class ExperienceOrb extends Entity {
 
     private short experienceCount;
 
-    public ExperienceOrb(short experienceCount) {
-        super(EntityType.EXPERIENCE_ORB);
+    public ExperienceOrb(short experienceCount, @NotNull Position spawnPosition) {
+        super(EntityType.EXPERIENCE_ORB, spawnPosition);
         setGravity(0.02f);
         setBoundingBox(0.5f, 0.5f, 0.5f);
         this.experienceCount = experienceCount;
     }
 
+    public ExperienceOrb(short experienceCount, @NotNull Position spawnPosition, @Nullable Instance instance) {
+        this(experienceCount, spawnPosition);
+
+        if (instance != null) {
+            setInstance(instance);
+        }
+    }
+
     @Override
     public void update(long time) {
         // TODO slide toward nearest player

src/main/java/net/minestom/server/entity/ItemEntity.java

@@ -2,6 +2,7 @@ package net.minestom.server.entity;
 
 import net.minestom.server.event.entity.EntityItemMergeEvent;
 import net.minestom.server.instance.Chunk;
+import net.minestom.server.instance.Instance;
 import net.minestom.server.item.ItemStack;
 import net.minestom.server.item.StackingRule;
 import net.minestom.server.utils.Position;
@@ -45,6 +46,14 @@ public class ItemEntity extends ObjectEntity {
         setBoundingBox(0.25f, 0.25f, 0.25f);
     }
 
+    public ItemEntity(@NotNull ItemStack itemStack, @NotNull Position spawnPosition, @Nullable Instance instance) {
+        this(itemStack, spawnPosition);
+
+        if (instance != null) {
+            setInstance(instance);
+        }
+    }
+
     /**
      * Gets the update option for the merging feature.
      *

src/main/java/net/minestom/server/event/player/PlayerSpawnEvent.java

@@ -6,7 +6,7 @@ import net.minestom.server.instance.Instance;
 import org.jetbrains.annotations.NotNull;
 
 /**
- * Called when a new instance is set for a player
+ * Called when a new instance is set for a player.
  */
 public class PlayerSpawnEvent extends EntitySpawnEvent {