@Test
 public void test_returnCorrectGPA() {
   System.out.println("Test correct gpa for a grade is returned...");
   CourseEnrollment C = new CourseEnrollment("java", 3, "A");
   double gpa = C.getGPAForGrade(C.getGrade());
   assertTrue(gpa >= 3.0 && gpa <= 4.0);
 }
 @Test
 public void test_setCorrectGrade() {
   System.out.println("Test correct Grade is set...");
   CourseEnrollment C = new CourseEnrollment("java", 4, "B");
   C.setGrade("C");
   assertTrue(C.getGrade().equals("C"));
 }
 @Test
 public void test_returnCorrectgrade() {
   System.out.println("Test correct Grade is returned...");
   CourseEnrollment C = new CourseEnrollment("english 202", 4, "B");
   assertTrue(C.getGrade().equals("B"));
 }