code: function( data, url ){
          var ns;
          if ( data.Image ) {
              ns = data.Image.xmlns;
          } else if ( data.documentElement) {
              if ("Image" == data.documentElement.localName || "Image" == data.documentElement.tagName) {
                  ns = data.documentElement.namespaceURI;
              }
          }
  
          ns = (ns || '').toLowerCase();
  
          return (ns.indexOf('schemas.microsoft.com/deepzoom/2008') !== -1 ||
              ns.indexOf('schemas.microsoft.com/deepzoom/2009') !== -1);
      }
docs: Determine if the data and/or url imply the image service is supported by
  this tile source.
  @function
  @param {Object|Array} data
  @param {String} optional - url