Prior to JDK 22, the `javac` compiler was accepting private method references with a type variable receiver. This implies that the `javac` compiler was accepting code like:

```
import java.util.function.*;
class Test {
    private String asString() {
        return "bar";
    }

    static <T extends Test> Function<T, String> foo() {
        return T::asString;
    }
}
```

Starting from JDK 22 private method references with type variable receiver will be rejected by the `javac` compiler.