public async Task Fail_CostHasBeenRecalled_Empty_CostId() { //Arrange var costId = Guid.Empty; var costOwnerId = _costOwnerId; //Act bool result = await _emailNotificationService.CostHasBeenRecalled(costId, costOwnerId); //Assert result.Should().BeFalse(); _paperPusherClientMock.Verify(p => p.SendMessage(It.IsAny <EmailNotificationMessage <CostNotificationObject> >()), Times.Never); }