public void Test()
        {
            Assert.That(Singleton.IsInitialized, Is.False);

            var singleton1 = Singleton.Accessor();

            Assert.That(Singleton.IsInitialized, Is.True);
            Assert.That(singleton1, Is.Not.Null);

            var singleton2 = Singleton.Accessor();

            Assert.That(singleton2, Is.Not.Null);
            Assert.That(singleton1, Is.SameAs(singleton2));
        }