public void Add_2() { var spanner = new StringSource("hey there"); var sub = spanner.Substring(new Range(4, 8)); var sub2 = spanner.Substring(new Range(3, 8)); var sub3 = spanner.Substring(new Range(0, 2)); spanner.TrimStart(' '); spanner.ToString().Should().Be("hey there"); sub.Deleted.Should().BeFalse(); sub.ToString().Should().Be("there"); sub2.ToString().Should().Be(" there"); sub3.Deleted.Should().BeFalse(); sub3.ToString().Should().Be("hey"); spanner.Add(" boy"); spanner.ToString().Should().Be("hey there boy"); sub.Deleted.Should().BeFalse(); sub.ToString().Should().Be("there"); sub2.ToString().Should().Be(" there"); sub3.Deleted.Should().BeFalse(); sub3.ToString().Should().Be("hey"); }