pub type KeyEnter<K, T, R, TEnter> = TraceEnter<TraceFrontier<TraceAgent<ColKeySpine<K, T, R>>>, TEnter>;
struct KeyEnter<K, T, R, TEnter> {
trace: TraceFrontier<TraceAgent<Spine<Rc<OrdKeyBatch<TStack<((K, ()), T, R)>>>, ColumnatedMergeBatcher<K, (), T, R>, RcBuilder<OrdKeyBuilder<TStack<((K, ()), T, R)>>>>>>,
stash1: Antichain<<TraceFrontier<TraceAgent<Spine<Rc<OrdKeyBatch<TStack<((K, ()), T, R)>>>, ColumnatedMergeBatcher<K, (), T, R>, RcBuilder<OrdKeyBuilder<TStack<((K, ()), T, R)>>>>>> as TraceReader>::Time>,
stash2: Antichain<TEnter>,
}