code: function hasRightSideContent() {
              var walker = new TreeWalker(container, parentBlock), node;
              var nonEmptyElementsMap = editor.schema.getNonEmptyElements();
  
              while ((node = walker.next())) {
                if (nonEmptyElementsMap[node.nodeName.toLowerCase()] || node.length > 0) {
                  return true;
                }
              }
            }
docs: Walks the parent block to the right and look for BR elements