Unable to save AnjularJS model using Object.assign()

I am trying to save model into mongo collection using the following statement

...
        createRecord: (body) => {
            console.log("Hello you are in createRecord : " );
            let sEntry = new SAudit(Object.assign({}, body ));
            console.log("Hello: " + body );
            console.log("Hello before saving: " + sEntry );
           return sEntry.save();
        }
...

Here, sEntry is blank even after performing Object.assign({}, body )

console.log is always blank
Hello before saving: { notes: [] }

Looks like I need to replace let sEntry = new SAudit(Object.assign({}, body ));

Source: AngularJS