code: function isValidContainer(node) {
    return !!(node && (node.nodeType === ELEMENT_NODE || node.nodeType === DOCUMENT_NODE || node.nodeType === DOCUMENT_FRAGMENT_NODE || node.nodeType === COMMENT_NODE && node.nodeValue === ' react-mount-point-unstable '));
  }
docs: True if the supplied DOM node is a valid node element.
  
  @param {?DOMElement} node The candidate DOM node.
  @return {boolean} True if the DOM is a valid DOM node.
  @internal