caching in loopback mixin using operation hooks

[Optimus2297]

Model.observe('access', function (context, cb) {
// check the cache
// short-cirtcuit to cb(null, cached) when found
});

Model.observe('loaded', function (context, cb) {
// update the cache
});
i am using these hooks for caching data through a mixin, but the response is still coming from Db and not from cache even if the callback is happening. I have also tried ctx.end(null, res) instead of callback but then i am getting the error as ctx.end is not a function. i want to send the response from the hook if the data is available in the cache object.