public void GetBuilderByBlockIndex_returns_existent_builders()
{
var graphBuilder = new BasicBlockGraphBuilder();
var first = graphBuilder.GetInitialBlockBuilder();
// Out-of-bounds indices are not tolerated
Assert.That(() => graphBuilder.GetBuilderByBlockIndex(1), Throws.InstanceOf <ArgumentOutOfRangeException>());
var second = graphBuilder.GetNewBasicBlock();
Assert.That(graphBuilder.GetBuilderByBlockIndex(0), Is.SameAs(first));
Assert.That(graphBuilder.GetBuilderByBlockIndex(1), Is.SameAs(second));
}