KeyValueChanges

  interface KeyValueChanges<K, V> { forEachItem(fn: (r: KeyValueChangeRecord<K, V>) => void): void; forEachPreviousItem(fn: (r: KeyValueChangeRecord<K, V>) => void): void; forEachChangedItem(fn: (r: KeyValueChangeRecord<K, V>) => void): void; forEachAddedItem(fn: (r: KeyValueChangeRecord<K, V>) => void): void; forEachRemovedItem(fn: (r: KeyValueChangeRecord<K, V>) => void): void;}