Minor cleanup.

Hey, sorry if this is noise, I've been reading the codebase today and just cleaning very minor things up as I see them. If you don't want to be bothered with this small stuff, let me know.

Two questions:

1) It seems like a lot of vars/defs that could be private are left public--is this intentional? When trying to read the codebase, I like as many "private" fields/methods as possible, because it helps me understand the object's true API. Would you like me to add private modifiers as I come across places that can have them?

2) It seems like "splits_", with the underscore last to denote the field, is a common convention, but it makes for odd type declarations because then you have to do "splits_ : Type" instead of just "_splits: Type" (note the extra space because "splits_:" makes the colon a part of the identifier). This probably doesn't matter, but I don't mind doing trivial/boring changes like s/split_/_split/ if it's okay with you guys.