@Override
    public int getDeserializerIdentifier() {
      return DESERIALIZER_IDENTIFIER;
    }
Used deserializing blocks from Cache. <code>
++++++++++++++
+ HFileBlock +
++++++++++++++
+ Checksums  + <= Optional
++++++++++++++
+ Metadata!  + <= See note on BLOCK_METADATA_SPACE above.
++++++++++++++
</code>
@see #serialize(ByteBuffer, boolean)
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlock.java