@Test
 public void higherThan89IsA() {
   String expectedResult = "A";
   String actualresult = ScoreAssigner.assignScore(90);
   assertEquals(expectedResult, actualresult);
 }
 @Test
 public void lessThan60IsF() {
   String expectedResult = "F";
   String actualresult = ScoreAssigner.assignScore(59);
   assertEquals(expectedResult, actualresult);
 }
 @Test
 public void higherThan69LessThan80IsC() {
   String expectedResult = "C";
   String actualresult = ScoreAssigner.assignScore(70);
   assertEquals(expectedResult, actualresult);
 }
 @Test
 public void higherThan59LessThan70IsD() {
   String expectedResult = "D";
   String actualresult = ScoreAssigner.assignScore(60);
   assertEquals(expectedResult, actualresult);
 }
 @Test
 public void higherThan79LessThan90IsB() {
   String expectedResult = "B";
   String actualresult = ScoreAssigner.assignScore(80);
   assertEquals(expectedResult, actualresult);
 }