public void plus(final Pair<String, AbstractVcs> pair) {
   final AbstractVcs vcs = pair.getSecond();
   if (RemoteDifferenceStrategy.ASK_TREE_PROVIDER.equals(vcs.getRemoteDifferenceStrategy())) {
     myRemoteRevisionsStateCache.plus(pair);
   } else {
     myRemoteRevisionsNumbersCache.plus(pair);
   }
 }