From 52f705d2390a26aac4919099621a86e6a6110176 Mon Sep 17 00:00:00 2001
From: Atif Aziz <code@raboof.com>
Date: Thu, 12 Jan 2023 21:46:34 +0100
Subject: [PATCH] Seal (private) enumerators

---
 MoreLinq/Permutations.cs | 2 +-
 MoreLinq/Subsets.cs      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/MoreLinq/Permutations.cs b/MoreLinq/Permutations.cs
index 0fac1001b..b700e46fc 100644
--- a/MoreLinq/Permutations.cs
+++ b/MoreLinq/Permutations.cs
@@ -29,7 +29,7 @@ public static partial class MoreEnumerable
         /// The private implementation class that produces permutations of a sequence.
         /// </summary>
 
-        class PermutationEnumerator<T> : IEnumerator<IList<T>>
+        sealed class PermutationEnumerator<T> : IEnumerator<IList<T>>
         {
             // NOTE: The algorithm used to generate permutations uses the fact that any set
             //       can be put into 1-to-1 correspondence with the set of ordinals number (0..n).
diff --git a/MoreLinq/Subsets.cs b/MoreLinq/Subsets.cs
index 357a60f73..3ddf9f49a 100644
--- a/MoreLinq/Subsets.cs
+++ b/MoreLinq/Subsets.cs
@@ -123,7 +123,7 @@ sealed class SubsetGenerator<T> : IEnumerable<IList<T>>
             /// predetermined size less than or equal to the original set size.
             /// </summary>
 
-            class SubsetEnumerator : IEnumerator<IList<T>>
+            sealed class SubsetEnumerator : IEnumerator<IList<T>>
             {
                 readonly IList<T> _set;   // the original set of elements
                 readonly T[] _subset;     // the current subset to return