@Override
 public long set(Map<String, String> keyValues, Atomicity atomicity) {
   return errorHandler.wrapLongCall(delegate.set_bulk(keyValues, atomicity.value()), -1);
 }
 @Override
 public Map<String, String> get(List<String> keys, Atomicity atomicity) {
   return errorHandler.wrapObjectCall(delegate.get_bulk(keys, atomicity.value()));
 }
 @Override
 public long remove(List<String> keys, Atomicity atomicity) {
   return errorHandler.wrapLongCall(delegate.remove_bulk(keys, atomicity.value()), -1);
 }
 @Override
 public byte[][] get(byte[][] keys, Atomicity atomicity) {
   return errorHandler.wrapObjectCall(delegate.get_bulk(keys, atomicity.value()));
 }