def key_finish
import bend-collections@1.0.0.0/src/containers/balanced_search_tree.bend as BalancedSearchTreeimport Base
578def key_finish(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, r: TreeMap<K, V, cmp> & Node<K>) -> TreeMap<K, V, cmp> & Maybe<&2, K>:
579 (m, node) = r
580 (m, node_key(~K, node))