@VisibleForTesting
  String testDump() {
    StringBuilder sb = new StringBuilder();
    for (Arena a : arenas) {
      a.testDump(sb);
    }
    return sb.toString();
  }
Unsets the headers (meaning this does not refer to a buffer).
llap-server/src/java/org/apache/hadoop/hive/llap/cache/BuddyAllocator.java