public async Task Fail_CostHasBeenCancelled_Empty_CostId()
        {
            //Arrange
            Guid costId = Guid.Empty;

            //Act
            bool result = await _emailNotificationService.CostHasBeenCancelled(costId);

            //Assert
            result.Should().BeFalse();
            _paperPusherClientMock.Verify(p => p.SendMessage(It.IsAny <EmailNotificationMessage <CostNotificationObject> >()), Times.Never);
        }