code: private List<Data> loadAndGet(List<Data> keys) {
          try {
              Map entries = mapDataStore.loadAll(keys);
              return getKeyValueSequence(entries);
          } catch (Throwable t) {
              logger.warning("Could not load keys from map store", t);
              throw ExceptionUtil.rethrow(t);
          }
      }
docs: Loads the provided keys from the underlying map store
  and transforms them to a list of alternating serialised key-value pairs.
  
  @param keys the keys for which values are loaded
  @return the list of loaded key-values
  @see com.hazelcast.core.MapLoader#loadAll(Collection)