I'm sorry but a `reducer` isn't a 90s-era Java concept at all [0], and you don't actually need to use any of those other things. This is beyond ridiculous.
[0] https://en.wikipedia.org/wiki/Fold_(higher-order_function)
[0] https://en.wikipedia.org/wiki/Fold_(higher-order_function)
All this has happened before. It will happen again
Hardly comparable to Java Servlets.