--- a/net/minecraft/world/IInventory.java
+++ b/net/minecraft/world/IInventory.java
@@ -9,6 +9,11 @@
 import net.minecraft.world.level.World;
 import net.minecraft.world.level.block.entity.TileEntity;
 
+// CraftBukkit start
+import net.minecraft.world.item.crafting.RecipeHolder;
+import org.bukkit.craftbukkit.entity.CraftHumanEntity;
+// CraftBukkit end
+
 public interface IInventory extends Clearable {
 
     float DEFAULT_DISTANCE_BUFFER = 4.0F;
@@ -25,9 +30,7 @@
 
     void setItem(int i, ItemStack itemstack);
 
-    default int getMaxStackSize() {
-        return 99;
-    }
+    int getMaxStackSize(); // CraftBukkit
 
     default int getMaxStackSize(ItemStack itemstack) {
         return Math.min(this.getMaxStackSize(), itemstack.getMaxStackSize());
@@ -91,4 +94,22 @@
 
         return world == null ? false : (world.getBlockEntity(blockposition) != tileentity ? false : entityhuman.canInteractWithBlock(blockposition, (double) f));
     }
+
+    // CraftBukkit start
+    java.util.List<ItemStack> getContents();
+
+    void onOpen(CraftHumanEntity who);
+
+    void onClose(CraftHumanEntity who);
+
+    java.util.List<org.bukkit.entity.HumanEntity> getViewers();
+
+    org.bukkit.inventory.InventoryHolder getOwner();
+
+    void setMaxStackSize(int size);
+
+    org.bukkit.Location getLocation();
+
+    int MAX_STACK = 99;
+    // CraftBukkit end
 }