PushSender client = DefaultPushSender.withRootServerURL("http://aerogear.example.com/ag-push")

                .proxy("proxy", 8080)

                .proxyType(Proxy.Type.HTTP)

                .build();

PushSender client = DefaultPushSender.withConfig("/path/on/classpath/push-config.json").build();

PushSender client = DefaultPushSender.withConfig(inputstream).build();