Mongoose.js: how to implement create or update?

I have a request which body contains data and _id

What is the better way to implement code that will update if record with _id exists and will create one is there is no one? My code:

var obj = req.body;
Model.findById(obj._id, function(err, data){
    if (!data){
        var model = new Model(obj)
        model.save(function(err, data){
            res.send({method: 'create', error: err, data: data})
        })
    } else {
        Model.findByIdAndUpdate(obj._id, obj, function(){
            res.send({method: 'update', error: err, data: data})
        })
    }

I'm just thinking maybe there is beter way of doing this.