Router.map(function() {
  this.route('exception');
  this.route('index', { path: '/' });

  this.route("login");

  this.route('change-sets', { path: 'change-sets' });
  this.route('change-set', { path: 'change-sets/:id' });
});

http://127.0.0.1:8000/api/change-set/change-set/250/document/3/

downloadChangeSet() {
  var changeSet = get(this, 'changeSet');
  var csID = changeSet.id;
  var link = "http://demo-box:8000/api/change-set/change-set/"+csID+"/document/3/";
  console.log(changeSet.id);
  window.open(link, "_self");

}