// special constructor for generating a given subblock of a strided map
    static RCP<StridedMap> Build(const RCP<const StridedMap>& map, LocalOrdinal stridedBlockId) {
      TEUCHOS_TEST_FOR_EXCEPTION(stridedBlockId < 0, Exceptions::RuntimeError,
                                 "Xpetra::StridedMapFactory::Build: constructor expects stridedBlockId > -1.");
      TEUCHOS_TEST_FOR_EXCEPTION(map->getStridedBlockId() != -1, Exceptions::RuntimeError,
                                 "Xpetra::StridedMapFactory::Build: constructor expects a full map (stridedBlockId == -1).");

      std::vector<size_t> stridingInfo = map->getStridingData();

      Teuchos::ArrayView<const GlobalOrdinal> dofGids = map->getNodeElementList();
      // std::sort(dofGids.begin(),dofGids.end()); // TODO: do we need this?

      // determine nStridedOffset
      size_t nStridedOffset = 0;
      for (int j = 0; j < map->getStridedBlockId(); j++)
        nStridedOffset += stridingInfo[j];

      size_t numMyBlockDofs = (stridingInfo[stridedBlockId] * map->getNodeNumElements()) / map->getFixedBlockSize();
      std::vector<GlobalOrdinal> subBlockDofGids(numMyBlockDofs);

      // TODO fill vector with dofs
      LocalOrdinal ind = 0;
      for (typename Teuchos::ArrayView< const GlobalOrdinal >::iterator it = dofGids.begin(); it!=dofGids.end(); ++it)
        if (map->GID2StridingBlockId(*it) == Teuchos::as<size_t>(stridedBlockId))
          subBlockDofGids[ind++] = *it;

      const Teuchos::ArrayView<const LocalOrdinal> subBlockDofGids_view(&subBlockDofGids[0],subBlockDofGids.size());

      return rcp(new StridedMap(map->lib(), Teuchos::OrdinalTraits<global_size_t>::invalid(), subBlockDofGids_view, map->getIndexBase(), stridingInfo, map->getComm(), stridedBlockId, map->getNode()));
    }