@Override
 public void initialize(STREAM stream, BlockMetadata blockMetadata, boolean consecutiveBlock) {
   if (buffer == null) {
     buffer = new byte[bufferSize];
   }
   super.initialize(stream, blockMetadata, consecutiveBlock);
 }
 @Override
 public void initialize(STREAM stream, BlockMetadata blockMetadata, boolean consecutiveBlock) {
   if (length == null) {
     length = (int) new Configuration().getLong("fs.local.block.size", 32 * 1024 * 1024);
     LOG.debug("length init {}", length);
   }
   super.initialize(stream, blockMetadata, consecutiveBlock);
 }