code: protected void updateMixin(NodeData node)
     {
        NodeData prevData = (NodeData)cache.put(new CacheId(getOwnerId(), node.getIdentifier()), node, true);
        // prevent update NullNodeData
        if (!(prevData instanceof NullNodeData))
        {
           if (prevData != null)
           {
              // do update ACL if needed
              if (prevData.getACL() == null || !prevData.getACL().equals(node.getACL()))
              {
                 updateChildsACL(node.getIdentifier(), node.getACL());
              }
           }
           else if (LOG.isDebugEnabled())
           {
              LOG.debug("Previous NodeData not found for mixin update " + node.getQPath().getAsString());
           }
        }
     }
docs: Update Node's mixin and ACL.
  
  @param node NodeData