public void SetWorkerForWorld_sets_worker_for_world_twice() { using (var testWorker = new UnityTestWorker("someId", Vector3.zero)) { testWorker.RegisterSystems(); var exception = Assert.Throws <System.ArgumentException>(() => WorkerRegistry.SetWorkerForWorld(testWorker)); Assert.IsTrue(exception.Message.Contains("worker") && exception.Message.Contains("world")); } }