Can someone check my inventory utils class?

package Technomage3.Core.Utils;

import java.util.Iterator;

import Technomage3.Core.Utils.InventoryUtils.Inventory;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.ItemStack;

public class InventoryUtils {




public static class Inventory implements Iterable<ItemStack> {

	private IInventory inv;

	public Inventory(IInventory i){
		inv = i;
	}

	@Override
	public Iterator<ItemStack> iterator() {
		return new InventoryIterator();
	}


	public InventoryIterator inventoryIterator() {
		return new InventoryIterator();
	}

	public boolean containsStack(ItemStack stack){

		for(ItemStack s : this){

			if(ItemStack.areItemStacksEqual(stack, s))
				return true;

		}
		return false;
	}

	public boolean containsAll(Iterable<ItemStack> inv){

		for(ItemStack s : inv){

			if(!this.contains(s))
				return false;

		}
		return true;
	}

	public boolean removeStack(ItemStack s){

		if(!contains(s))
			return false;

		InventoryIterator itr = this.inventoryIterator();

		while(itr.hasNext()){

			if(itr.get().isItemEqual(s)){
				itr.remove();
				return true;
			}


			itr.next();

		}
		return true;
	}
	/**
	 * 
	 * @param stack2 the stack to try to remove
	 * @return the amount that was actually removed
	 */

	public ItemStack removeByItem(ItemStack stack2){

		ItemStack toTake = stack2.copy();

		for(ItemStack s : this){
			int b = toTake.stackSize;
			toTake = takeStack(toTake, s);
		}

		return new ItemStack(toTake.itemID, toTake.getItemDamage(), stack2.stackSize - toTake.stackSize);
	}

	public boolean canRemoveAll(ItemStack stack2) {

		ItemStack stack = stack2.copy();

		for(ItemStack s : this){
			stack = takeStackNoMod(stack, s);

			if(stack.stackSize <= 0 || stack == null)
				break;
		}

		return stack.stackSize <= 0 || stack == null;
	}

	/**
	 * removes either the entire stack or nothing from the inventory
	 * @param stack
	 * @return whether the stack was added
	 */
	public boolean removeIffCan(ItemStack stack){

		if(canRemoveAll(stack)){
			removeByItem(stack);
			return true;
		} else
			return false;


	}

	public boolean canAdd(ItemStack stack2) {

		ItemStack stack = stack2.copy();

		InventoryIterator itr = this.inventoryIterator();

		while(itr.hasNext()){

			ItemStack i = itr.get();

			if(i == null){
				return true;
			} else
				stack = mergeStacksNoMod(stack, i);

			if(stack == null || stack.stackSize == 0)
				return true;

			itr.next();
		}
		return stack == null || stack.stackSize == 0;
	}

	public ItemStack add(ItemStack stack){

		InventoryIterator itr = this.inventoryIterator();

		while(itr.hasNext()){

			ItemStack i = itr.get();

			if(i == null){
				itr.set(stack);
				return null;
			} else
				stack = mergeStacks(stack, i);

			itr.set(i);

			if(stack == null || stack.stackSize == 0)
				return stack;

			itr.next();
		}
		return stack;
	}

	/**
	 * adds either the entire stack or nothing into the inventory
	 * @param stack
	 * @return whether the stack was added
	 */
	public boolean addIffCan(ItemStack stack){

		if(canAdd(stack)){
			add(stack);
			return true;
		} else
			return false;


	}

	public boolean contains(ItemStack stack){

		ItemStack s = stack.copy();

		for(ItemStack i : this){

			if(areStacksCompatible(i, s)){
				s.stackSize -= i.stackSize;
			}

		}

		return s.stackSize <= 0;
	}

	/**
	 * 
	 * @param s the stack to search for
	 * @return the amount of room for s's items in the inventory
	 */
	public int getRoom(ItemStack s){

		int room = 0;

		for(ItemStack i : this){

			if(i == null){

				room += 64;

			} else if(areStacksCompatible(s, i)){
				room += i.getMaxStackSize() - i.stackSize;
			}

		}
		return room;
	}

	/**
	 * 
	 * @param s the stack to search for
	 * @return the amount of s's items in the inventory
	 */
	public int getAmount(ItemStack s){

		int have = 0;

		for(ItemStack i : this){

			if(i != null && areStacksCompatible(s, i)){
				have += i.stackSize;
			}

		}
		return have;

	}

	public class InventoryIterator implements Iterator<ItemStack> {

		private int pos;

		@Override
		public boolean hasNext() {
			return pos < inv.getSizeInventory() - 1;
		}

		@Override
		public ItemStack next() {
			return inv.getStackInSlot(++pos);
		}

		public ItemStack previous() {
			return inv.getStackInSlot(--pos);
		}

		@Override
		public void remove() {
			inv.setInventorySlotContents(pos, null);

		}

		public void set(ItemStack stack){
			inv.setInventorySlotContents(pos, stack);
		}

		public ItemStack get(){
			return inv.getStackInSlot(pos);
		}

		public int getSlot(){
			return pos;
		}

	}



}

public static Inventory getInventory(IInventory i){
	return new Inventory(i);
}

/**
 * 
 * Merges s2 into s1, and returns the extra of s2
 * 
 * @param s1
 * @param s2
 * @return the extra of s2
 */
public static ItemStack mergeStacks(ItemStack s1, ItemStack s2) {

	if(areStacksCompatible(s1, s2))
		return s2;

	int room = Math.min(s1.getMaxStackSize() - s1.stackSize, s2.stackSize);

	if(room <= 0)
		return s2;

	s1.stackSize += room;
	s2.stackSize -= room;

	if(s2.stackSize == 0)
		return null;
	else
		return s2;

}

/**
 * 
 * Simulates mergeing s2 into s1, and returns the extra of s2
 * 
 * @param s1
 * @param s2
 * @return the extra of s2
 */
private static ItemStack mergeStacksNoMod(ItemStack s1, ItemStack s2) {

	if(areStacksCompatible(s1, s2))
		return s2;

	int room = Math.min(s1.getMaxStackSize() - s1.stackSize, s2.stackSize);

	if(room <= 0)
		return s2;


	s2.stackSize -= room;

	if(s2.stackSize == 0)
		return null;
	else
		return s2;

}

/**
 * 
 * @param toTake the goal amount to take
 * @param from the stack to take from
 * @return what still has to be taken (the remainder of toTake)
 */
public static ItemStack takeStack(ItemStack toTake, ItemStack from){

	if(!areStacksCompatible(toTake, from))
		return toTake;

	int take = Math.min(from.stackSize, toTake.getMaxStackSize() - toTake.stackSize);

	toTake.stackSize -= take;
	from.stackSize -= take;

	return toTake;
}

/**
 * 
 * @param toTake the goal amount to take
 * @param from the stack to take from
 * @return what still has to be taken (the remainder of toTake)
 */
private static ItemStack takeStackNoMod(ItemStack toTake, ItemStack from){

	if(!areStacksCompatible(toTake, from))
		return toTake;

	int take = Math.min(from.stackSize, toTake.getMaxStackSize() - toTake.stackSize);

	toTake.stackSize -= take;

	return toTake;
}

public static boolean areStacksCompatible(ItemStack s1, ItemStack s2){

	return s1.itemID == s2.itemID && s1.getItemDamage() == s2.getItemDamage();

}

/**
 * 
 * transfers as much as possible of goal from pullFrom into pushTo
 * 
 * @param pushTo the inventory to push items to
 * @param stack the stack to try to transfer
 * @param pullFrom the inventory to take items from
 */
public static void transferStack(Inventory pushTo, ItemStack goal,
		Inventory pullFrom) {

	int toTransfer = Math.min(goal.stackSize, Math.min(pushTo.getRoom(goal), pullFrom.getAmount(goal)));

	pushTo.add(pullFrom.removeByItem(new ItemStack(goal.itemID, goal.getItemDamage(), toTransfer)));

}

}