[Test] public void AddIfAbsentDoesAddWhenNotExist()
{
var sut = new CopyOnWriteList <T>(Samples);
sut.AddIfAbsent(TestData <T> .M1);
Assert.IsTrue(sut.Contains(TestData <T> .M1));
}
[Test] public void AddIfAbsentDoesNotAddWhenExist()
{
var sut = new CopyOnWriteList <T>(Samples);
sut.AddIfAbsent(TestData <T> .One);
Assert.That(sut.Count, Is.EqualTo(SampleSize));
}