Apply php-cs-fixer fix --rules nullable_type_declaration_for_default_…

…null_value

GenericRuntime.php

@@ -86,7 +86,7 @@ public function __construct(array $options = [])
     /**
      * {@inheritdoc}
      */
-    public function getResolver(callable $callable, \ReflectionFunction $reflector = null): ResolverInterface
+    public function getResolver(callable $callable, ?\ReflectionFunction $reflector = null): ResolverInterface
     {
         if (!$callable instanceof \Closure) {
             $callable = \Closure::fromCallable($callable);

Runner/Symfony/ConsoleApplicationRunner.php

@@ -27,7 +27,7 @@ class ConsoleApplicationRunner implements RunnerInterface
     private $input;
     private $output;
 
-    public function __construct(Application $application, ?string $defaultEnv, InputInterface $input, OutputInterface $output = null)
+    public function __construct(Application $application, ?string $defaultEnv, InputInterface $input, ?OutputInterface $output = null)
     {
         $this->application = $application;
         $this->defaultEnv = $defaultEnv;

RuntimeInterface.php

@@ -23,7 +23,7 @@ interface RuntimeInterface
      *
      * The callable itself should return an object that represents the application to pass to the getRunner() method.
      */
-    public function getResolver(callable $callable, \ReflectionFunction $reflector = null): ResolverInterface;
+    public function getResolver(callable $callable, ?\ReflectionFunction $reflector = null): ResolverInterface;
 
     /**
      * Returns a callable that knows how to run the passed object and that returns its exit status as int.