Returning unresolved InetSocketAddress from resolution filter method

I have a use case where I would like a filter to be able to modify a request hostname/port, but still use the proxy's default host name resolver (i.e. not resolve the address in the filter). I've added a check to ProxyToServerConnection.setupConnectionParameters() so that if the filter does return an unresolved address, it will attempt to resolve it using the usual proxy resolver.