[Debug] Mark the ErrorHandler and ExceptionHandler classes as final

src/Symfony/Component/Debug/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.3.0
+-----
+
+* made the `ErrorHandler` and `ExceptionHandler` classes final
+
 4.0.0
 -----
 

src/Symfony/Component/Debug/ErrorHandler.php

@@ -45,6 +45,8 @@ use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;
  *
  * @author Nicolas Grekas <p@tchwork.com>
  * @author Grégoire Pineau <lyrixx@lyrixx.info>
+ *
+ * @final since Symfony 4.3
  */
 class ErrorHandler
 {

src/Symfony/Component/Debug/ExceptionHandler.php

@@ -26,6 +26,8 @@ use Symfony\Component\HttpKernel\Debug\FileLinkFormatter;
  *
  * @author Fabien Potencier <fabien@symfony.com>
  * @author Nicolas Grekas <p@tchwork.com>
+ *
+ * @final since Symfony 4.3
  */
 class ExceptionHandler
 {