diff --git a/np_collection/lib/src/map_extension.dart b/np_collection/lib/src/map_extension.dart
index d0833dc0..88bbd922 100644
--- a/np_collection/lib/src/map_extension.dart
+++ b/np_collection/lib/src/map_extension.dart
@@ -11,4 +11,6 @@ extension MapExtension<T, U> on Map<T, U> {
         entries.map((e) async => await convert(e.key, e.value)));
     return Map.fromEntries(results);
   }
+
+  Map<T, U> addedAll(Map<T, U> other) => {...this, ...other};
 }
diff --git a/np_collection/lib/src/set_util.dart b/np_collection/lib/src/set_util.dart
index 9c9819d0..0becce79 100644
--- a/np_collection/lib/src/set_util.dart
+++ b/np_collection/lib/src/set_util.dart
@@ -1,5 +1,6 @@
 extension SetExtension<T> on Set<T> {
   Set<T> added(T element) => toSet()..add(element);
+  Set<T> addedAll(Iterable<T> elements) => toSet()..addAll(elements);
 
   Set<T> removed(T element) => toSet()..remove(element);
 }