docs: function genClassForVnode (vnode) {
  	  var data = vnode.data;
  	  var parentNode = vnode;
  	  var childNode = vnode;
  	  while (childNode.child) {
  	    childNode = childNode.child._vnode;
  	    if (childNode.data) {
  	      data = mergeClassData(childNode.data, data);
  	    }
  	  }
  	  while ((parentNode = parentNode.parent)) {
  	    if (parentNode.data) {
  	      data = mergeClassData(data, parentNode.data);
  	    }
  	  }
  	  return genClassFromData(data)
  	}