An automatically-expanding buffer of longs.
A Cache that is keyed by a long.
A Navigable Set which casts to and from two types which are the same (usually, T is a subtype of V), but which is prevented from pretty access because of Java Generics Rules.
Iterator which is designed around the idea that a stream will feed items until exhausted, at which point it will feed null.
Simple non-thread-safe ring buffer.