sanity check in insert

[gballet]

No description provided.

[s1na]

Looks good. leaf.Insert is being called by leaf.InsertOrdered, but I couldn't find where leaf.InsertOrdered itself is being called to this code might be right now unused.

[gballet]

yeah, it shouldn't be called. Might as well panic in any case. This is just here in case we switch to an iterative approach, and the code will be incorrect in that case anyway. I'll mull it over.

The code is currently unused, but that's because we haven't tried updating values. This function (or maybe one very similar called Update) should indeed update the code.

[gballet]

Closing, this is mixing Insert and Update.