From c8dff9d6f6b62f22094489cc8597d57aa996e32b Mon Sep 17 00:00:00 2001
From: Kevin Moore <kevmoo@google.com>
Date: Tue, 15 Nov 2022 20:12:25 -0800
Subject: [PATCH] Revert change to Optional

Breaks too many things
---
 CHANGELOG.md               | 1 -
 lib/src/core/optional.dart | 9 +++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33f414f2..e6bd2455 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,5 @@
 #### 3.2.0-dev
 
-  * Explicitly disallow a `nullable` type argument for `Optional`.
   * Expose `TreeIterator` for iterating `TreeSet` instead of using
     `BidirectionalIterator`.
   * Require Dart 2.17
diff --git a/lib/src/core/optional.dart b/lib/src/core/optional.dart
index 42ab9e51..ec1e98c6 100644
--- a/lib/src/core/optional.dart
+++ b/lib/src/core/optional.dart
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// ignore_for_file: null_check_on_nullable_type_parameter
+
 import 'dart:collection';
 
 /// A value that might be absent.
@@ -23,7 +25,7 @@ import 'dart:collection';
 /// With the introduction of non-null by default in Dart SDK 2.12, developers
 /// should avoid adding more uses of this type. Existing users should migrate
 /// away from the `Optional` type to types marked nullable: `T?`.
-class Optional<T extends Object> extends IterableBase<T> {
+class Optional<T> extends IterableBase<T> {
   /// Constructs an empty Optional.
   const Optional.absent() : _value = null;
 
@@ -90,7 +92,7 @@ class Optional<T extends Object> extends IterableBase<T> {
   /// If the Optional is [absent()], returns [absent()] without applying the transformer.
   ///
   /// The transformer must not return [null]. If it does, an [ArgumentError] is thrown.
-  Optional<S> transform<S extends Object>(S Function(T value) transformer) {
+  Optional<S> transform<S>(S Function(T value) transformer) {
     return _value == null
         ? Optional<S>.absent()
         : Optional<S>.of(transformer(_value!));
@@ -101,8 +103,7 @@ class Optional<T extends Object> extends IterableBase<T> {
   /// If the Optional is [absent()], returns [absent()] without applying the transformer.
   ///
   /// Returns [absent()] if the transformer returns [null].
-  Optional<S> transformNullable<S extends Object>(
-      S? Function(T value) transformer) {
+  Optional<S> transformNullable<S>(S? Function(T value) transformer) {
     return _value == null
         ? Optional<S>.absent()
         : Optional<S>.fromNullable(transformer(_value!));