private void unblock(@NotNull Node vertex) {
    myBlocked.remove(vertex);
    Set<Node> bSet = getBSet(vertex);
    while (bSet.size() > 0) {
      Node w = bSet.iterator().next();
      bSet.remove(w);
      if (myBlocked.contains(w)) {
        unblock(w);
      }
    }
  }
private void unblock(@NotNull Node vertex)