public Set keysWithoutCreatesForTests() {
    checkReadiness();
    Set<Integer> availableBuckets = new HashSet<>();
    for (int i = 0; i < getTotalNumberOfBuckets(); i++) {
      if (distAdvisor.isStorageAssignedForBucket(i)) {
        availableBuckets.add(i);
      }
    }
    return Collections.unmodifiableSet(new KeysSet(availableBuckets));
  }
Get a keyset of the given buckets
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java