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