code: @Override
      public boolean add(BannerAdPreset expressAdPreset) {
          return !(expressAdPreset == null || !expressAdPreset.isValid())
                  && super.add(expressAdPreset);
      }
docs: Tries to add an item to collection if it is valid {@link BannerAdPreset#isValid()}
  @return true if item was added, false - otherwise