Prior to JDK 25, the `javac` compiler was allowing the type of lambda expressions to be classes in some cases. This implies that the `javac` compiler was accepting code like:

```
    class Test {
        void m() {
            Test r = (Test & Runnable) () -> System.out.println("Hello, World!");
        }
    }
```

Starting from JDK 25 the `javac` compiler will reject lambda expressions which type is a class