checker/tests/nullness/generics/Issue421.java

public class Issue421<IE> {
  abstract static class C<CE> {
    abstract X<? extends CE> getX();
  }

  interface X<T> {}

  abstract static class R<RE> {
    abstract boolean d(X<? extends RE> id);
  }

  private void f(C<IE> c, R<IE> r) {
    X<? extends IE> x = c.getX();
    boolean bval = r.d(x);
  }
}