public void AddTutorErrorTest4()
{
//// Arrange
var errors = new List <string>();
var mockRepository = new Mock <InterfaceInstructorRepository>();
var instructorService = new InstructorService(mockRepository.Object);
//// Act
instructorService.AddTutor(100, 1, "John", null, ref errors);
//// Assert
Assert.AreEqual(1, errors.Count);
}