This could be written pretty trivially using an Ordering, but I fear for the performance characteristics here, since this is a fast path. How does this look:
```
if (pairs.isEmpty || other.pairs.isEmpty) {
   -pairs.length.compareTo(other.pairs.length)
} else {
  -minKeyHash.compareTo(other.minKeyHash)
}
```
I think we may also need the `-` sign in front of the length for the same reason as we have it in the hash -- we want to invert the ordering since we deque the max not the min.