/// <summary>
        /// Update Test Result
        /// </summary>
        /// <param name="test"></param>
        public void UpdateTestResult(BE.Test test)
        {
            int indexTest = tests.FindIndex(t => t.TestID == test.TestID);

            if (indexTest == -1)
            {
                throw new KeyNotFoundException("לא נמצא מבחן שמספרו " + test.TestID);
            }
            tests[indexTest] = test.Clone();
            SaveToXML <List <Test> >(tests, testsPath);
        }
 /// <summary>
 /// Add Test
 /// </summary>
 /// <param name="test"></param>
 public void AddTest(BE.Test test)
 {
     tests.Add(test.Clone());
     SaveToXML <List <Test> >(tests, testsPath);
 }