* instead of {@code Comparator<? super T>}.
   */
  public void testMinMaxWithSupertypeComparator() {
    Comparator<Number> numberComparator =
        // Can't use Comparator.comparing(Number::intValue) due to Java 7 compatibility.
        new Comparator<Number>() {
          @Override
          public int compare(Number a, Number b) {
            return a.intValue() - b.intValue();
          }
        };
    Integer comparand1 = 1;