Function getReactRootElementInContainer

docs/lib/react.js:11166–11176

* @param {DOMElement|DOMDocument} container DOM element that may contain * a React component * @return {?*} DOM element that may have the reactRoot ID, or null.

(container)

 * @return {?*} DOM element that may have the reactRoot ID, or null.
 */
function getReactRootElementInContainer(container) {
  if (!container) {
    return null;
  }

  if (container.nodeType === DOC_NODE_TYPE) {
    return container.documentElement;
  } else {
    return container.firstChild;
  }
}

function internalGetID(node) {
  // If node is something like a window, document, or text node, none of