In Chapter 8, there's a section called How Not To Work With Optional values.
Can you summarize in one sentence what are the gotchas to watch out for when designing and using APIs that exposes optional values ?
As far as I'm concerned, nulls in the JVM is an impediment to using java.util.Optional ? It applies to Enums as well.
P.S. The book contains too much introductory material for me to fork out the money for it.