In JDK-8281289, the SSLParameters class was updated with the patch:
- return Collections.<SNIServerName>unmodifiableList(new ArrayList<>(sniNames.values()));
+ return List.copyOf(sniNames.values());

However, there's a small compatibility risk with this change, `List.copyOf(...).contains(null)` will throw NPE while `Collections.unmodifiableList(...).contains(null)` won't. It may be not worthy of the risk although the impact may be minimal.