// Test case for Issue 1399.
// https://github.com/typetools/checker-framework/issues/1399

public class Issue1399 {
    static class Box<T> {
        static <T> Box<T> box(Class<T> type) {
            return new Box<T>();
        }

        void act(T instance) {}
    }

    abstract class Math {
        abstract <T> Box<T> id(Box<T> in);

        void foo(Math m) {
            m.id(Box.box(Long.class)).act(10L);
        }
    }
}