Need help in store.unloadAll test

i m getting error of unknown function when i write the test of unloadAll

route : model function model(){ this.store.unloadAll(‘userModel’); return [‘1’,‘2’] },

test :

test(‘unloadAll function test’, function(assert) { let done = assert.async(); var route = this.subject();

let store = Ember.Object.create({ unloadAll(‘userModel’) { assert.equal(‘userModel’, ‘userModel’); return new Ember.RSVP.Promise(function(resolve) { resolve(); }); } }); route.set(‘store’, store); route.model().then(function(model) { done(); });

});