code: function () {
              if (!this.props.visible) {
                  return;
              }
  
              var node = Preact.findDOMNode(this),
                  selectedNode = $(node.parentNode).find(this.props.selectedClassName).closest("li"),
                  selectionViewInfo = this.props.selectionViewInfo;
  
              if (selectedNode.length === 0) {
                  return;
              }
  
              var top = selectedNode.offset().top,
                  baselineHeight = node.dataset.initialHeight,
                  height = baselineHeight,
                  scrollerTop = selectionViewInfo.get("offsetTop");
  
              if (!baselineHeight) {
                  baselineHeight = $(node).outerHeight();
                  node.dataset.initialHeight = baselineHeight;
                  height = baselineHeight;
              }
  
              // Check to see if the selection is completely scrolled out of view
              // to prevent the extension from appearing in the working set area.
              if (top < scrollerTop - baselineHeight) {
                  node.style.display = "none";
                  return;
              }
  
              node.style.display = "block";
  
              // The selectionExtension sits on top of the other nodes
              // so we need to shrink it if only part of the selection node is visible
              if (top < scrollerTop) {
                  var difference = scrollerTop - top;
                  top += difference;
                  height = parseInt(height, 10);
                  height -= difference;
              }
  
              node.style.top = top + "px";
              node.style.height = height + "px";
              node.style.left = selectionViewInfo.get("width") - $(node).outerWidth() + "px";
          }
docs: When the component has updated in the DOM, reposition it to where the currently
  selected node is located now.