basic promises rest

app.get("/", function(req, res){
    fetchModel()
        //Second Call
        .then(scanDifferences /*, **Function for on reject** */)
        //Third Call
        .then(insertNewones /*, **Function for on reject** */)
        //Last Call
        .done(function(promise){
            res.json({"Name": "Hello"})
        });
});