public BufferChunk getChunk() {
      return chunk;
    }
Fake cache chunk used for uncompressed data. Used in preRead for uncompressed files.
Makes assumptions about preRead code; for example, we add chunks here when they are
already in the linked list, without unlinking. So, we record the start position in the
original list, and then, when someone adds the next element, we merely increase the number
of elements one has to traverse from that position to get the whole list.
ql/src/java/org/apache/hadoop/hive/ql/io/orc/encoded/EncodedReaderImpl.java