declare type ReadonlyCollection<K, V> = Omit<Collection<K, V>, 'delete' | 'ensure' | 'forEach' | 'get' | 'reverse' | 'set' | 'sort' | 'sweep'> & ReadonlyMap<K, V>;

declare type ReadonlyCollection<K, V> = Omit<Collection<K, V>, 'delete' | 'ensure' | 'forEach' | 'get' | 'reverse' | 'set' | 'sort' | 'sweep'> & ReadonlyMap<K, V>;