Sometimes, you may need to manipulate and transform the data that is being emitted from a stream before it gets to its final destination.
This is extremely useful when you want to filter data based on any type of condition, validate it, modify data before showing it to your users, or process it to generate some new output.
Examples include converting a number into a string, or making a calculation, or omitting data repetitions.
In this recipe, you will inject StreamTransformers into Streams in order to map and filter data.
