@Override
 protected ByteIterable[] getByteIterables(@NotNull final ReclaimFlag flag) {
   return new ByteIterable[] {
     CompressedUnsignedLongByteIterable.getIterable((size << 1) + flag.value), // store flag bit
     CompressedUnsignedLongArrayByteIterable.getIterable(keysAddresses, size)
   };
 }
 @Override
 public long save() {
   return root.save(
       this, new MutableNodeSaveContext(CompressedUnsignedLongByteIterable.getIterable(size)));
 }