Function insertBefore

docs/external/js/react-dom.development.js:7713–7715

(parentInstance, child, beforeChild)

    }
  }
  function insertBefore(parentInstance, child, beforeChild) {
    parentInstance.insertBefore(child, beforeChild);
  }
  function insertInContainerBefore(container, child, beforeChild) {
    if (container.nodeType === COMMENT_NODE) {
      container.parentNode.insertBefore(child, beforeChild);