Maps: SequencedMap adds first and last operations

SequencedMap<String, Integer> steps = new LinkedHashMap<>();
steps.put("build", 2);
steps.put("test", 3);
steps.putFirst("checkout", 1);
steps.putLast("deploy", 4);

System.out.println(steps);
System.out.println("firstEntry = " + steps.firstEntry());
System.out.println("lastEntry  = " + steps.lastEntry());
System.out.println("reversed   = " + steps.reversed());

{checkout=1, build=2, test=3, deploy=4}
firstEntry = checkout=1
lastEntry  = deploy=4
reversed   = {deploy=4, test=3, build=2, checkout=1}