diff --git a/lib/dart_extensions.dart b/lib/dart_extensions.dart
index ee7ebdc..bb964c9 100644
--- a/lib/dart_extensions.dart
+++ b/lib/dart_extensions.dart
@@ -24,6 +24,7 @@ export 'package:dart_extensions/src/flutter/container.dart';
 export 'package:dart_extensions/src/flutter/gesture_detector.dart';
 export 'package:dart_extensions/src/flutter/navigation.dart';
 export 'package:dart_extensions/src/flutter/padding.dart';
+export 'package:dart_extensions/src/equality.dart';
 export 'package:dart_extensions/src/http.dart';
 export 'package:dart_extensions/src/int.dart';
 export 'package:dart_extensions/src/iterable.dart';
@@ -32,4 +33,3 @@ export 'package:dart_extensions/src/search_algorithms.dart';
 export 'package:dart_extensions/src/sort_algorithms.dart';
 export 'package:dart_extensions/src/string_ext.dart';
 export 'package:dart_extensions/src/flutter/widgets.dart';
- 
diff --git a/lib/src/iterable.dart b/lib/src/iterable.dart
index c0f60f9..a510ad8 100644
--- a/lib/src/iterable.dart
+++ b/lib/src/iterable.dart
@@ -27,7 +27,7 @@ extension CollectionsNullableExtensions<T> on Iterable<T>? {
   ///Returns `true` if this nullable iterable is either null or empty.
   bool get isEmptyOrNull => (this?.isEmpty ?? true);
 
-    /// Returns `true` if at least one element matches the given [predicate].
+  /// Returns `true` if at least one element matches the given [predicate].
   bool any(bool predicate(T element)) {
     if (this.isEmptyOrNull) return false;
     for (final element in this.orEmpty()) if (predicate(element)) return true;
@@ -52,7 +52,9 @@ extension CollectionsNullableExtensions<T> on Iterable<T>? {
   /// the combination of them two.
   zip<T>(Iterable<T> iterable) sync* {
     if (iterable.isEmptyOrNull) return;
-    final iterables = List<Iterable>.empty()..add(this.orEmpty())..add(iterable);
+    final iterables = List<Iterable>.empty()
+      ..add(this.orEmpty())
+      ..add(iterable);
 
     final iterators = iterables.map((e) => e.iterator).toList(growable: false);
     while (iterators.every((e) => e.moveNext())) {
@@ -65,9 +67,10 @@ extension CollectionsExtensions<T> on Iterable<T> {
   ///Sorts elements in the array in-place according to natural sort order of the value returned by specified [selector] function.
   Iterable<T> sortBy<TKey>(
     TKey Function(T) keySelector, {
-    required EqualityComparer<TKey> keyComparer,
+    EqualityComparer<TKey>? keyComparer,
   }) {
-    return InternalOrderedIterable(this, keySelector, keyComparer, false);
+    return InternalOrderedIterable(
+        this, keySelector, keyComparer ?? EqualityComparer<TKey>(), false);
   }
 
   /// Convert iterable to set
@@ -205,7 +208,8 @@ extension CollectionsExtensions<T> on Iterable<T> {
   T firstOrDefault(T defaultValue) => firstOrNull ?? defaultValue;
 
   /// Will retrun new [Iterable] with all elements that satisfy the predicate [predicate],
-  Iterable<T> whereIndexed(IndexedPredicate<T> predicate) => _IndexedWhereIterable(this, predicate);
+  Iterable<T> whereIndexed(IndexedPredicate<T> predicate) =>
+      _IndexedWhereIterable(this, predicate);
 
   ///
   /// Performs the given action on each element on iterable, providing sequential index with the element.
@@ -365,7 +369,8 @@ extension CollectionsExtensions<T> on Iterable<T> {
   Iterable<List<T>> chunks(int size) => partition(this, size);
 
   /// Creates a Map instance in which the keys and values are computed from the iterable.
-  Map<dynamic, dynamic> associate(key(element), value(element)) => Map.fromIterable(this, key: key, value: value);
+  Map<dynamic, dynamic> associate(key(element), value(element)) =>
+      Map.fromIterable(this, key: key, value: value);
 
   /// Returns the first element matching the given [predicate], or `null`
   /// if element was not found.