type ReadonlyCollection<Key, Value> = Omit<Collection<Key, Value>, keyof Map<Key, Value> | 'each' | 'ensure' | 'reverse' | 'sort' | 'sweep' | 'tap'> & ReadonlyMap<Key, Value> & { each(fn: (value: Value, key: Key, collection: ReadonlyCollection<Key, Value>) => void): ReadonlyCollection<Key, Value>; each<This>(fn: (this: This, value: Value, key: Key, collection: ReadonlyCollection<Key, Value>) => void, thisArg: This): ReadonlyCollection<Key, Value>; tap(fn: (collection: ReadonlyCollection<Key, Value>) => void): ReadonlyCollection<Key, Value>; tap<This>(fn: (this: This, collection: ReadonlyCollection<Key, Value>) => void, thisArg: This): ReadonlyCollection<Key, Value>;};Represents an immutable version of a collection