code: public void setImageAssets(com.google.api.ads.admanager.axis.v201808.CreativeAsset[] imageAssets) {
          this.imageAssets = imageAssets;
      }
docs: Sets the imageAssets value for this AspectRatioImageCreative.
  
  @param imageAssets   * The images associated with this creative. The ad server will
  choose one
  based on the capabilities of the device. Each
  asset should have a size
  which is of the same aspect ratio as the {@link
  Creative#size}. This
  attribute is required and must have at least one
  asset.