I think the contents of this file should be on TracingExampleApp.scala, or if in a separate file, UpperCaser.scala is not a good name for it! Also, let me abuse a little bit of your kindness :D, as we discussed earlier we still need to extend the traces documentation to talk about finishing a trace and showing that it isn't just TraceContext propagation but also about collecting metrics out of those traces.. how do you feel about extending the example with a call to `TraceRecorder.finish(..)` and writing a simple subscriber that prints the metrics to the console?