```
  public IQueryable<T> All()
    {
        var session = _sessionFactory.GetCurrentSession();
        return FilterByClientId(from r in session.Query<T>() select r);
    }

    public IQueryable<T> FilterByClientId(IQueryable<T> queryable)
    {
        return queryable.Where(row => _clientIds.ClientIds.Contains<long>(row.ClientId) );
    }

```

Can I make use of Custom Attribute on the method to handle the decoration? the resulting code would look something like this. call to All method with the ClientFilter would automatically decorate the result. 

```
[ClientFilter]
    public IQueryable<T> All()
    {
        var session = _sessionFactory.GetCurrentSession();
        return from r in session.Query<T>() select r;
    }

```