public void FindUpperBound()
{
var values = new[] { 1, 1, 3, 3 };
Assert.That(values.FindUpperBound(4), Is.EqualTo(3));
Assert.That(values.FindUpperBound(3), Is.EqualTo(3));
Assert.That(values.FindUpperBound(2), Is.EqualTo(1));
Assert.That(values.FindUpperBound(1), Is.EqualTo(1));
Assert.That(values.FindUpperBound(0), Is.EqualTo(-1));
}