message: feat(core): KeyValueDiffer#diff allows null values
  PR Close
diff: @@ -468,10 +468,10 @@ export interface KeyValueChanges<K, V> {
  }
  export interface KeyValueDiffer<K, V> {
  - diff(object: Map<K, V>): KeyValueChanges<K, V>;
  + diff(object: Map<K, V>): KeyValueChanges<K, V> | null;
  diff(object: {
  [key: string]: V;
  - }): KeyValueChanges<string, V>;
  + }): KeyValueChanges<string, V> | null;
  }
  export interface KeyValueDifferFactory {
  