Here is my code:
public static class bettermushroomstab extends ItemGroup {
public bettermushroomstab(String label) {
super("bettermushroomstab");
this.setBackgroundImage("Bettermushroomstab.png");
}
private void setBackgroundImage(String string) {
// TODO Auto-generated method stub
}
@Override
public ItemStack makeIcon() {
return ItemInit.COOKEDMUSHROOM.get().getDefaultInstance();
}
}