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)); }