void (String[] args) { // Breakpoint! final long count = StreamEx.of(1, 2, 3) .peekFirst(System.out::print) .peekLast(System.out::print) .mapToEntry(x -> x * x) .peekKeys(System.out::print) .peekValues(System.out::print) .peekKeyValue((k, v) -> System.out.println("(" + k + " -> " + v + ")")) .count(); System.out.println(count); }