in a callout "Using flatMap()" by Boyarsky, Jeanne. OCP Oracle Certified Professional Java SE 11 Developer Complete Study Guide (p. 712). Wiley. Kindle Edition.
There is a strange example of using flatMap to create int stream... Why would you use a flat map for this example? FlatMap is used to flatten the content of the collection, and here the collection is ready to be streamed as is, right?