public void Should_Not_Have_Validation_Error_If_City_Is_Not_Empty()
        {
            var validator = new GetForecastByCityValidator();
            var model     = new GetForecastByCityQuery("Hamburg", null, null);
            var result    = validator.TestValidate(model);

            result.ShouldNotHaveValidationErrorFor(x => x.City);
        }
        public void Should_Have_Validation_Error_If_City_Is_Null()
        {
            var validator = new GetForecastByCityValidator();
            var model     = new GetForecastByCityQuery(null, null, null);
            var result    = validator.TestValidate(model);

            result.ShouldHaveValidationErrorFor(x => x.City)
            .WithErrorMessage("'City' must not be empty.")
            .WithSeverity(Severity.Error)
            .WithErrorCode("NotEmptyValidator");
        }