Namespace using layout

I'm sure it used to be possible to automatically format namespaces as follows...

using System;
using System.Net;
using System.Threading.Tasks;
using System.Web.Http;

using Bar.Core;
using Bar.Data;

using Foo.Data;
using Foo.FileStore;

i.e. with a blank line between each of the groups, but I can't remember how to set this in Resharper anymore