While I agree that @2beaucoup's suggestion would provide the cleaner and leaner API here there is one thing that is rather ugly about these DNS lookups (`getByName` / `getAllByName`): they are inherently blocking, potentially for a non-insignificant amount of time.

By moving them into the `HttpClientConnection` actor we'd effectively remove them completely from the control of the user. If we keep them where they are the user could manage the lookups him/herself (even potentially move them out underneath a dedicated dispatcher), so I'd prefer to *not* move them into the `HttpClientConnection` actor.