changedByOthers.cs

_subscription = DocumentStoreHolder.Store
    .Changes()
    .ForDocument(CategoryIdTextbox.Text)
    .Where(change =>
    {
        if (!_justSaved) return true;
        _justSaved = false;
        var localEtag = _session.Advanced.GetEtagFor(_category);

        var numberOfServerChanges = change.Etag.Changes - localEtag.Changes;
        return numberOfServerChanges > 1;
    })
    .Subscribe(DocumentChangedOnServer);