Issue459.java

import org.checkerframework.checker.nullness.qual.*;

public class Issue459 {
    public class Generic<K, V> {}

    interface Iface<K, V> {
        public <K1 extends K, V1 extends V> Generic<K, V> foo(Generic<? super K1, ? super V1> arg);

        public <K2 extends K, V2 extends V> Generic<K, V> foo2(
                Generic<? super K2, ? super V2> arg, K2 strArg);
    }

    void f(Iface<Object, Object> arg, @NonNull String nnString) {
        final Generic<String, Integer> obj = new Generic<String, Integer>();
        arg.foo(obj);

        final Generic<@Nullable String, Integer> obj2 = new Generic<@Nullable String, Integer>();
        arg.foo2(obj2, nnString);
    }
}