code: function() {
  
        // create a canvas element
        var canvas = document.createElement('canvas');
  
        // define a context var that will be used for browsers with canvas support
        var ctx;
  
        // try/catch for older browsers that don't support the canvas element
        try {
  
          // attempt to give ctx a 2d canvas context value
          ctx = canvas.getContext('2d');
  
        } catch (e) {
  
          // return empty string if canvas element not supported
          return "";
        }
  
        // https://www.browserleaks.com/canvas#how-does-it-work
        // Text with lowercase/uppercase/punctuation symbols
        var txt = 'ClientJS,org <canvas> 1.0';
        ctx.textBaseline = "top";
        // The most common type
        ctx.font = "14px 'Arial'";
        ctx.textBaseline = "alphabetic";
        ctx.fillStyle = "#f60";
        ctx.fillRect(125, 1, 62, 20);
        // Some tricks for color mixing to increase the difference in rendering
        ctx.fillStyle = "#069";
        ctx.fillText(txt, 2, 15);
        ctx.fillStyle = "rgba(102, 204, 0, 0.7)";
        ctx.fillText(txt, 4, 17);
        return canvas.toDataURL();
      }
docs: Get Canvas Print.  Return a string containing the canvas URI data.