src/java.base/share/classes/java/time/zone/ZoneRules.java

@@ -968,11 +968,11 @@
      * daylight saving time. The list will also be empty if the transition rules are unknown.
      *
      * @return an immutable list of transition rules, not null
      */
     public List<ZoneOffsetTransitionRule> getTransitionRules() {
-        return Collections.unmodifiableList(Arrays.asList(lastRules));
+        return List.of(lastRules);
     }
 
     /**
      * Checks if this set of rules equals another.
      * <p>