anchor.diff:  
               // Create a canvas
               // https://github.com/scijs/get-pixels/blob/7c447cd979637b31e47e148f238a1e71611af481/dom-pixels.js#L14-L18
  -            var canvasEl = document.createElement('canvas');
  +            var canvasEl = D.CANVAS({class: 'updated-ref'});
               canvasEl.width = refImg.naturalWidth;
               canvasEl.height = refImg.naturalHeight;
               var context = canvasEl.getContext('2d');
  
positive.code:               currentImg: imageSetEl.querySelector('[data-compare-type=current]'),
                diffImg: imageSetEl.querySelector('[data-compare-type=diff]'),
                refImg: imageSetEl.querySelector('[data-compare-type=ref]'),
                humanName: imageSetEl.getAttribute('data-image-set')
              };
              if (imageSetEl === expectedImgSetEl) {
  
negative.code:           // Run acceptance function
            acceptImageSetChanges(base64Data, imgSetId);
          });
  
          $('body').on('click', 'button[data-action="update-similar-images"]', function handleClick (evt) {
            // Find our image set container
            var btnEl = evt.target;
            var $imgSet = $(btnEl).closest('[data-image-set]');
            //- assert.strictEqual($imgSet.length, 1);
  
            // Find our similar image sets
            var $similarImageSets = $imgSet.find('[data-similar-image-set]');
            //- assert.strictEqual($currentImg.length, 1);
  
            // For each of our similar image sets
            $similarImageSets.each(function updateImageSet (i, similarImageSetEl) {
              // Move back to jQuery collection
              var $similarImageSet = $(similarImageSetEl);
              var similarImgSetId = $similarImageSet.data('similar-image-set');
  
              // If the image set wasn't selected, then return
              if ($similarImageSet.find('[name=save_update]').prop('checked') !== true) {
                return;
              }
  
              // Extract updated base64 content
              var $updatedRefCanvas = $similarImageSet.find('.updated-ref');
              //- assert.strictEqual($updatedRefCanvas.length, 1);
              var base64Data = $updatedRefCanvas[0].toDataURL('image/png');
  
              // Run acceptance function
              //- updateImageSetChanges(base64Data, similarImgSetId);
              console.log(base64Data, similarImgSetId);
            });
          });
        });
  
      script.
  