Save a dashboard's metadata

def save_dash(self, dashboard_id):
        """Save a dashboard's metadata"""
        session = db.session()
        dash = (session
                .query(models.Dashboard)
                .filter_by(id=dashboard_id).first())
        check_ownership(dash, raise_if_false=True)
        data = json.loads(request.form.get('data'))
        self._set_dash_metadata(dash, data)
        session.merge(dash)
        session.commit()
        session.close()
        return json_success(json.dumps({'status': 'SUCCESS'}))