docs: public void hasValue(Object expected) {
      if (expected == null) {
        throw new NullPointerException("Optional cannot have a null value.");
      }
      if (actual() == null) {
        failWithActual("expected an optional with value", expected);
      } else if (!actual().isPresent()) {
        failWithoutActual(fact("expected to have value", expected), simpleFact("but was absent"));
      } else {
        checkNoNeedToDisplayBothValues("get()").that(actual().get()).isEqualTo(expected);
      }
    }