pub type Drain<'a, K, V> = DynTrait<'a, RBox<()>, ValIterInterface<K, V>>;
An RHashMap iterator, implementing Iterator<Item= Tuple2< K, V > > + !Send + !Sync
Iterator<Item= Tuple2< K, V > > + !Send + !Sync
struct Drain<'a, K, V> { /* private fields */ }