code: public com.google.api.ads.adwords.axis.v201809.cm.AssetLink[] getMarketingImages() {
          return marketingImages;
      }
docs: Gets the marketingImages value for this MultiAssetResponsiveDisplayAd.
  
  @return marketingImages   * Marketing image to be used in the ad. This ad format does not
  allow the creation of an
  imageAsset using the ImageAsset.imageData field.
  An imageAsset must first be created using the
  AssetService, and ImageAsset.assetId must be populated
  in this field. Valid image types are
  GIF, JPEG, and PNG. The minimum size is 600x314
  and the aspect ratio must be 1.91:1 (+-1%). One
  marketingImage is required. Support up to 15 with
  squareMarketingImages.
  <span class="constraint Selectable">This field
  can be selected using the value "MultiAssetResponsiveDisplayAdMarketingImages".</span>
  <span class="constraint Required">This field is required and should
  not be {@code null} when it is contained within {@link Operator}s
  : ADD.</span>