public long countClusterElements(final int[] iClusterIds) {
   checkOpeness();
   return underlying.countClusterElements(iClusterIds);
 }
 public long countClusterElements(final String iClusterName) {
   checkOpeness();
   return underlying.countClusterElements(iClusterName);
 }
 @Override
 public long countClusterElements(int[] iClusterIds, boolean countTombstones) {
   checkOpeness();
   return underlying.countClusterElements(iClusterIds, countTombstones);
 }