Consider this rule/script:
---
$foo = $map.get($key);
if ($foo == null) {
    $foo = $expr$;
    $map.put($key, $foo);
} :: $map instanceof java.util.Map
=>
$foo = $map.computeIfAbsent($key, p -> $expr$);
;;
---

And this sample file:
---
        Map<String, String> map = new HashMap<>();
        String foo;
        String key = "";
        foo = map.get(key);
        if (foo == null) {
            foo = "";
            map.put(key, foo);
        }
---

Applying the transformation leads to:
        foo = map.computeIfAbsent(key, (<any> p) -> (""));
which is not ideal.

This is on:

Product Version: NetBeans IDE 8.0 (Build 20140315-f817edfd05cd)
Java: 1.8.0; Java HotSpot(TM) 64-Bit Server VM 25.0-b70
Runtime: Java(TM) SE Runtime Environment 1.8.0-b132
System: Linux version 3.16.0-30-generic running on amd64; UTF-8; en_US (nb)
User directory: /usr/local/home/lahvac/.netbeans/dev
Cache directory: /usr/local/home/lahvac/.netbeans/dev/var/cache