@Override
        public int compare(OffsettedItem item1, OffsettedItem item2) {
          ItemType type1 = item1.itemType();
          ItemType type2 = item2.itemType();
          return type1.compareTo(type2);
        }
{@code non-null;} sorter which sorts instances by type
android/android_framework/dex-maker/src/main/java/com/android/dx/dex/file/MixedItemSection.java