public void state_controller_build_fails_without_default_state()
{
Assert.Throws <InvalidOperationException>(() => builder.Build());
Assert.Throws <InvalidOperationException>(() => builder.Build());
builder.WithDefaultState(new TestState());
nonEmptyBuilder.WithDefaultState(new TestState());
Assert.DoesNotThrow(() => builder.Build());
Assert.DoesNotThrow(() => builder.Build());
}