private void checkHeaderByte(
      int arenaIx, int headerIx, int freeListIx, boolean isLocked, byte header) {
    if (isLocked != ((header & 1) == 1)) {
      failWithLog("Expected " + arenaIx + ":" + headerIx + " "
          + (isLocked ? "" : "not ") + "locked: " + header);
    }
    if (freeListIx < 0) return;
    if (freeListFromHeader(header) != freeListIx) {
      failWithLog("Expected " + arenaIx + ":" + headerIx + " in list " + freeListIx
          + ": " + freeListFromHeader(header));
    }
  }
Unsets the headers (meaning this does not refer to a buffer).
llap-server/src/java/org/apache/hadoop/hive/llap/cache/BuddyAllocator.java