public void ContainDuplicatesTestWithNoDuplicates()
 {
     HasDuplicates HD = new HasDuplicates();
     HD.ContainDuplicates(new int[] { 1, 2, 3, 4, 41, 42 }).Should().Be(false);
 }
 public void ContainDuplicatesTestWithNullInput()
 {
     HasDuplicates HD = new HasDuplicates();
     Action action = () => HD.ContainDuplicates(null);
     action.ShouldThrow<ArgumentException>();
 }
 public void ContainDuplicatesTestWithEmptyArray()
 {
     HasDuplicates HD = new HasDuplicates();
     Action action = () => HD.ContainDuplicates(new int[] {});
        action.ShouldThrow<ArgumentException>();
 }