code: function(options) {
          $.console.assert(options, "[Viewer.addSimpleImage] options is required");
          $.console.assert(options.url, "[Viewer.addSimpleImage] options.url is required");
  
          var opts = $.extend({}, options, {
              tileSource: {
                  type: 'image',
                  url:  options.url
              }
          });
          delete opts.url;
          this.addTiledImage(opts);
      }
docs: Add a simple image to the viewer.
  The options are the same as the ones in {@link OpenSeadragon.Viewer#addTiledImage}
  except for options.tileSource which is replaced by options.url.
  @function
  @param {Object} options - See {@link OpenSeadragon.Viewer#addTiledImage}
  for all the options
  @param {String} options.url - The URL of the image to add.
  @fires OpenSeadragon.World.event:add-item
  @fires OpenSeadragon.Viewer.event:add-item-failed