public Pair<List<RepositoryLocationGroup>, List<RepositoryLocation>> groupLocations(
        final List<RepositoryLocation> in) {
      final List<RepositoryLocationGroup> groups = new ArrayList<RepositoryLocationGroup>();
      final List<RepositoryLocation> singles = new ArrayList<RepositoryLocation>();

      final MultiMap<SVNURL, RepositoryLocation> map = new MultiMap<SVNURL, RepositoryLocation>();

      for (RepositoryLocation location : in) {
        final SvnRepositoryLocation svnLocation = (SvnRepositoryLocation) location;
        final String url = svnLocation.getURL();

        final SVNURL root = SvnUtil.getRepositoryRoot(myVcs, url);
        if (root == null) {
          // should not occur
          LOG.info("repository root not found for location:" + location.toPresentableString());
          singles.add(location);
        } else {
          map.putValue(root, svnLocation);
        }
      }

      final Set<SVNURL> keys = map.keySet();
      for (SVNURL key : keys) {
        final Collection<RepositoryLocation> repositoryLocations = map.get(key);
        if (repositoryLocations.size() == 1) {
          singles.add(repositoryLocations.iterator().next());
        } else {
          final SvnRepositoryLocationGroup group =
              new SvnRepositoryLocationGroup(key, repositoryLocations);
          groups.add(group);
        }
      }
      return new Pair<List<RepositoryLocationGroup>, List<RepositoryLocation>>(groups, singles);
    }
 @Override
 protected void doInAwtIfFail(Exception e) {
   final Exception cause;
   if (e instanceof MyRuntime) {
     cause = (Exception) e.getCause();
   } else {
     cause = e;
   }
   LOG.info(e);
   VcsBalloonProblemNotifier.showOverChangesView(
       myProject, cause.getMessage(), MessageType.ERROR);
 }