@Override
  public HFileBlock touch(Object hint) {
    bufWithoutChecksum.touch(hint);
    return this;
  }
Calling this method in strategic locations where HFileBlocks are referenced may help diagnose
potential buffer leaks. We pass the block itself as a default hint, but one can use
{@link #touch(Object)} to pass their own hint as well.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlock.java