function findDOMNode(componentOrElement) {
  if ("development" !== 'production') {
    var owner = ReactCurrentOwner.current;
    if (owner !== null) {
      "development" !== 'production' ? warning(owner._warnedAboutRefsInRender, '%s is accessing getDOMNode or findDOMNode inside its render(). ' + 'render() should be a pure function of props and state. It should ' + 'never access something that requires stale data from the previous ' + 'render, such as refs. Move this logic to componentDidMount and ' + 'componentDidUpdate instead.', owner.getName() || 'A component') : undefined;
      owner._warnedAboutRefsInRender = true;
    }
  }
  if (componentOrElement == null) {
    return null;
  }
  if (componentOrElement.nodeType === 1) {
    return componentOrElement;
  }
  if (ReactInstanceMap.has(componentOrElement)) {
    return ReactMount.getNodeFromInstance(componentOrElement);
  }
  !(componentOrElement.render == null || typeof componentOrElement.render !== 'function') ? "development" !== 'production' ? invariant(false, 'findDOMNode was called on an unmounted component.') : invariant(false) : undefined;
  !false ? "development" !== 'production' ? invariant(false, 'Element appears to be neither ReactComponent nor DOMNode (keys: %s)', Object.keys(componentOrElement)) : invariant(false) : undefined;
}
Returns the DOM node rendered by this element.

@param {ReactComponent|DOMElement} componentOrElement
@return {?DOMElement} The root node of this element.