in algebird-core/src/main/scala/com/twitter/algebird/Max.scala [145:153]
final override def compare(left: List[T], right: List[T]): Int =
(left, right) match {
case (Nil, Nil) => 0
case (Nil, _) => -1
case (_, Nil) => 1
case (lh :: lt, rh :: rt) =>
val c = Ordering[T].compare(lh, rh)
if (c == 0) compare(lt, rt) else c
}