@Override
      public boolean hasNext() {
        if (decompressedData == null) {
          return rawSize > 0;
        }
        return decompressedData.hasRemaining();
      }
Provides access to compressed value.
@param headerSize header size of the block.
@return Forwards sequential iterator.
hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/EncodedDataBlock.java