code: public com.google.api.ads.adwords.axis.v201809.cm.Image getSquareMarketingImage() {
          return squareMarketingImage;
      }
docs: Gets the squareMarketingImage value for this ResponsiveDisplayAd.
  
  @return squareMarketingImage   * Square marketing image to be used in the ad. This image may
  be used when a square aspect ratio
  is more appropriate than the aspect ratio of the
  {@link #marketingImage} image. This ad format
  does not allow the creation of an image using
  the Image.data field. An image must first be
  created using the MediaService, and Image.mediaId
  must be populated when creating a {@link
  "ResponsiveDisplayAd"}. Valid image types are
  GIF, JPEG, and PNG. The minimum size is 300x300
  the aspect ratio must be 1:1 (+-1%).
  <span class="constraint Selectable">This field
  can be selected using the value "SquareMarketingImage".</span>