private void collectFreeChunks(List<LongStack> l) {
    collectFreeFragmentChunks(l);
    collectFreeHugeChunks(l);
    collectFreeTinyChunks(l);
  }
Unit tests override this method to get better test coverage
geode-core/src/main/java/org/apache/geode/internal/offheap/FreeListManager.java