public void GivenCustomerNonExistingId_WhenCustomerById_ThenReturnBadRequestWithCustomerNotFoundExceptionMessage()
{
//Given
_customerServiceStub.GetCustomerById(-1).Returns(ex => { throw new CustomerNotFoundException(); });
//When
BadRequestObjectResult result = (BadRequestObjectResult)_customerController.GetCustomerBasedOnId(-1).Result;
//Then
Assert.Equal("Customer with this id does not exist", result.Value);
}