title: Getting all group names in signalr
body: <p>ok so I have this code</p>
  
  <pre><code>var c = GlobalHost.ConnectionManager.GetHubContext&lt;SomeHubClass&gt;().Clients;
  </code></pre>
  
  <p>now from this the Clients returns an IHubConext that has IHubConnectionContext that has an IGroupManager Groups. now is there anyway to get all the group names from this? Is this even possible with the signalR interface or do I have to track all the groups for each hub myself?</p>