.heappush!: |T: Type|(heap: Iterable(T), item: T) => NoneType # TODO: Push!
.heappop!: |T: Type|(heap: Iterable(T)) => T # TODO: Pop!
.heappushpop!: |T: Type|(heap: Iterable(T), item: T) => T # TODO: Push! and Pop!
.heapify!: (heap: List(Obj, _)) => NoneType