private static byte makeHeader(int freeListIx, boolean isInUse) {
    return (byte)(((freeListIx + 1) << 1) | (isInUse ? 1 : 0));
  }
Unsets the headers (meaning this does not refer to a buffer).
llap-server/src/java/org/apache/hadoop/hive/llap/cache/BuddyAllocator.java