public void CheckSingles()
 {
     Assert.Equal(15, Exercise001.Singles(new List <int> {
         4, 5, 7, 5, 4, 8
     }));
     Assert.Equal(19, Exercise001.Singles(new List <int> {
         9, 10, 19, 13, 19, 13
     }));
     Assert.Equal(12, Exercise001.Singles(new List <int> {
         16, 0, 11, 4, 8, 16, 0, 11
     }));
     Assert.Equal(22, Exercise001.Singles(new List <int> {
         5, 17, 18, 11, 13, 18, 11, 13
     }));
     Assert.Equal(24, Exercise001.Singles(new List <int> {
         5, 10, 19, 13, 10, 13
     }));
 }
 public void CheckSinglesAllDuplicates()
 {
     Assert.Equal(0, Exercise001.Singles(new List <int> {
         6, 6, 8, 8
     }));
 }