private int largestFragmentSize() {
    int largestFreeSpaceFromFragments = 0;
    for (Fragment f : fragmentList) {
      int fragmentFreeSpace = f.freeSpace();
      if (fragmentFreeSpace > largestFreeSpaceFromFragments) {
        largestFreeSpaceFromFragments = fragmentFreeSpace;
      }
    }
    return largestFreeSpaceFromFragments;
  }
Defragments memory and returns true if enough memory to allocate chunkSize is freed. Otherwise
returns false; Unlike the defragment method this method is not thread safe and does not check
for a concurrent defragment. It should only be called by defragment and unit tests.
geode-core/src/main/java/org/apache/geode/internal/offheap/FreeListManager.java