services
        .AddSlimMessageBus(mbb =>
        {
            mbb
                // add required serializers to the DI container first
                .AddAvroSerializer()
                .AddGoogleProtobufSerializer()
                .AddJsonSerializer()
                
                // Add hybrid serializer last so that it can update DI container and set itself as the default
                .AddHybridSerializer<JsonMessageSerializer>(
                    o => {

                        // Message1, Message2 => AvroSerializer
                        // Message3 => GoogleProtobufMessageSerializer
                        // all other messages by JsonMessageSerializer

                        o.Add<AvroSerializer>(typeof(Message1), typeof(Message2));
                        o.Add<GoogleProtobufMessageSerializer>(typeof(Message3));
                    })
                ...
        }