function getInstanceFromNode(node) {
	  var inst = getClosestInstanceFromNode(node);
	  if (inst != null && inst._hostNode === node) {
	    return inst;
	  } else {
	    return null;
	  }
	}
Given a DOM node, return the ReactDOMComponent or ReactDOMTextComponent
instance, or null if the node was not rendered by this React.