Seals a bunch of classes that need to be

src/Umbraco.Web/Cache/ContentTypeCacheRefresher.cs

@@ -9,7 +9,7 @@ using Umbraco.Core.Persistence.Caching;
 
 namespace Umbraco.Web.Cache
 {
-    public class ContentTypeCacheRefresher : ICacheRefresher<IContentType>, ICacheRefresher<IMediaType>
+    public sealed class ContentTypeCacheRefresher : ICacheRefresher<IContentType>, ICacheRefresher<IMediaType>
     {
         public Guid UniqueIdentifier
         {

src/Umbraco.Web/Cache/DistributedCache.cs

@@ -25,7 +25,7 @@ namespace Umbraco.Web.Cache
     /// 
     /// Dispatcher can refresh/remove content, templates and macros.
     /// </remarks>
-    public class DistributedCache
+    public sealed class DistributedCache
     {
 
         #region Public constants/Ids

src/Umbraco.Web/Cache/MacroCacheRefresher.cs

@@ -11,7 +11,7 @@ namespace Umbraco.Web.Cache
     /// <summary>
     /// Used to invalidate/refresh the cache for macros
     /// </summary>
-    public class MacroCacheRefresher : ICacheRefresher<Macro>, ICacheRefresher<macro>
+    public sealed class MacroCacheRefresher : ICacheRefresher<Macro>, ICacheRefresher<macro>
     {
         internal static string[] GetAllMacroCacheKeys()
         {

src/Umbraco.Web/Cache/MediaCacheRefresher.cs

@@ -6,7 +6,7 @@ using umbraco.interfaces;
 
 namespace Umbraco.Web.Cache
 {
-    public class MediaCacheRefresher : ICacheRefresher<IMedia>
+    public sealed class MediaCacheRefresher : ICacheRefresher<IMedia>
     {
         public Guid UniqueIdentifier
         {

src/Umbraco.Web/Cache/MemberCacheRefresher.cs

@@ -6,7 +6,7 @@ using umbraco.interfaces;
 
 namespace Umbraco.Web.Cache
 {
-    public class MemberCacheRefresher : ICacheRefresher<Member>
+    public sealed class MemberCacheRefresher : ICacheRefresher<Member>
     {
 
         public Guid UniqueIdentifier

src/Umbraco.Web/Cache/TemplateCacheRefresher.cs

@@ -6,7 +6,7 @@ using umbraco.interfaces;
 
 namespace Umbraco.Web.Cache
 {
-    public class TemplateCacheRefresher : ICacheRefresher
+    public sealed class TemplateCacheRefresher : ICacheRefresher
     {
         
         public string Name

src/Umbraco.Web/Cache/UserCacheRefresher.cs

@@ -8,7 +8,7 @@ namespace Umbraco.Web.Cache
     /// <summary>
     /// Handles User cache invalidation/refreshing
     /// </summary>
-    public class UserCacheRefresher : ICacheRefresher
+    public sealed class UserCacheRefresher : ICacheRefresher
     {
         public Guid UniqueIdentifier
         {