iter.hasNext();
      fail();
    } catch (IllegalStateException expected) {
    }
  }

  // Technically we should test other reentrant scenarios (9 combinations of
  // hasNext/next/peek), but we'll cop out for now, knowing that peek() and
  // next() both start by invoking hasNext() anyway.

  /** Throws an undeclared checked exception. */
  private static void sneakyThrow(Throwable t) {

      iter.hasNext();
      fail();
    } catch (IllegalStateException expected) {
    }
  }

  // Technically we should test other reentrant scenarios (9 combinations of
  // hasNext/next/peek), but we'll cop out for now, knowing that peek() and
  // next() both start by invoking hasNext() anyway.

  /** Throws an undeclared checked exception. */
  private static void sneakyThrow(Throwable t) {