title: What would be an appropriate replacement for ConnectionBackend with HttpClient?
body: <p>Working on a rewrite of an Angular 4 app and moving to Angular 8 in the process, the issue is I'm trying to get this interceptor working properly, what would be a replacement for <code>ConnectionBackend</code>? I see there's an <code>HttpBackend</code> but I'm not sure if it has api changes over <code>ConnectionBackend</code>. Currently it's only being passed as a parameter of the constructor.</p>