Java 9의 JShell에서 맵을 구현하는 방법은 무엇입니까?

<strong>C:\Users\User>jshell
| Welcome to JShell -- Version 9.0.4
| For an introduction type: /help intro

jshell> Map<String, String> map = new HashMap<String, String>();
map ==> {}

jshell> map.put("raja", "ramesh");
$2 ==> null

jshell> map.put("adithya", "sai");
$3 ==> null

jshell> map.put("jai", "dev");
$4 ==> null

jshell> map.put("chaintaya", "krishna");
$5 ==> null

jshell> Map<String, String> immutableMap = Collections.unmodifiableMap(map);
immutableMap ==> {raja=ramesh, jai=dev, chaintaya=krishna, adithya=sai}

jshell></strong>