code: function createNode(el, attr) {
  	// html comment is not currently supported by virtual-dom
  	if (el.nodeType === 3) {
  		return createVirtualTextNode(el);
  
  	// cdata or doctype is not currently supported by virtual-dom
  	} else if (el.nodeType === 1 || el.nodeType === 9) {
  		return createVirtualDomNode(el, attr);
  	}
  
  	// default to empty text node
  	return new VText('');
  }
docs: Create vdom from dom node
  
  @param   Object  el    DOM element
  @param   String  attr  Attribute name that contains vdom key
  @return  Object        VNode or VText