Example 1: internal iteration
Example 2: using predicates
Example 3: lazy computation
Example 4: pair of prime numbers computed with streams
Example 7: measure of sequential and parallel streams

Fork/Join framework behind this.
Example 8: functional core, side effect functions moved to outer layers
Example 10: using optionals in Java 8
Example 11: scala's loan pattern, or passing a block in ruby
Example 13: completable futures
Example 13: completable futures faster with executor