@Override
      void write(String value) {
        contentsOut.stringDatas.size++;
        idsDefsOut.writeInt(stringDataOut.getPosition());
        stringDataOut.writeStringData(value);
      }
minimum number of wasted bytes before it's worthwhile to compact the result
android/android_framework/dex-maker/src/main/java/com/android/dx/merge/DexMerger.java