public void SimpleTryDequeues()
{
var queue = ImmutableQueue <int> .Empty
.Enqueue(1)
.Enqueue(2)
.Enqueue(3);
int out1;
var r1 = Transactional.TryDequeue(ref queue, out out1);
r1.Should().BeTrue(nameof(r1));
out1.Should().Be(1);
int out2;
var r2 = Transactional.TryDequeue(ref queue, out out2);
r2.Should().BeTrue(nameof(r2));
out2.Should().Be(2);
int out3;
var r3 = Transactional.TryDequeue(ref queue, out out3);
r3.Should().BeTrue(nameof(r3));
out3.Should().Be(3);
int out4;
var r4 = Transactional.TryDequeue(ref queue, out out4);
r4.Should().BeFalse(nameof(r4));
out4.Should().Be(default(int));
}