private boolean isDuplicate(Bookmark bookmark, @NotNull VirtualFile file, @Nullable List<Bookmark> toRemove) {
      // it's quadratic but oh well. let's hope users are sane enough not to have thousands of bookmarks in one file.
      for (Bookmark b : myBookmarks.get(file)) {
        if (b == bookmark) continue;
        if (!b.isValid()) continue;
        if (Comparing.equal(b.getFile(), bookmark.getFile()) && b.getLine() == bookmark.getLine()) {
          if (toRemove == null || !toRemove.contains(b)) {
            return true;
          }
        }
      }
      return false;
    }
private boolean isDuplicate(Bookmark bookmark, @NotNull VirtualFile file, @Nullable List<Bookmark> toRemove)