private static void checkTestValue(
      LlapAllocatorBuffer mem, long testValue, String str, boolean mustExist) {
    if (!incRefIfNotEvicted(mem, mustExist)) return;
    try {
      TestBuddyAllocator.checkTestValue(mem, testValue, str);
    } finally {
      mem.decRef();
    }
  }
This relies on allocations basically being sequential, no internal reordering. Rather,
the specific paths it takes do; all the scenarios should work regardless of allocation.
llap-server/src/test/org/apache/hadoop/hive/llap/cache/TestBuddyAllocatorForceEvict.java