private static ValidationResults ValidateNoNullOrEmptyValues(ValidationResults results, AddCompanyWithOfficeCommand validatableObject)
        {
            results.ValidateNotNullOrEmpty(validatableObject.CompanyName, nameof(validatableObject.CompanyName));
            results.ValidateNotNullOrEmpty(validatableObject.CEO, nameof(validatableObject.CEO));
            results.ValidateNotNullOrEmpty(validatableObject.BuildingName, nameof(validatableObject.BuildingName));
            results.ValidateNotNullOrEmpty(validatableObject.Street, nameof(validatableObject.Street));
            results.ValidateNotNull(validatableObject.HouseNumber, nameof(validatableObject.HouseNumber));
            results.ValidateNotNullOrEmpty(validatableObject.City, nameof(validatableObject.City));

            return(results);
        }
        public void TestValidateNotNullWithNullValueShouldReturnValidationResults()
        {
            // Arrange

            var validationResults = new ValidationResults();
            int input             = -1;

            // Act

            validationResults.ValidateNotNull(input, "input");

            // Assert

            validationResults.GetMessages().Should().Be("input cannot be null");
        }