Apply php-cs-fixer fix --rules nullable_type_declaration_for_default_null_value

Author: nicolas-grekas

GatewayApiTransport.php

@@ -31,7 +31,7 @@ final class GatewayApiTransport extends AbstractTransport
     private $authToken;
     private $from;
 
-    public function __construct(string $authToken, string $from, HttpClientInterface $client = null, EventDispatcherInterface $dispatcher = null)
+    public function __construct(string $authToken, string $from, ?HttpClientInterface $client = null, ?EventDispatcherInterface $dispatcher = null)
     {
         $this->authToken = $authToken;
         $this->from = $from;

Tests/GatewayApiTransportTest.php

@@ -31,7 +31,7 @@ final class GatewayApiTransportTest extends TransportTestCase
     /**
      * @return GatewayApiTransport
      */
-    public static function createTransport(HttpClientInterface $client = null): TransportInterface
+    public static function createTransport(?HttpClientInterface $client = null): TransportInterface
     {
         return new GatewayApiTransport('authtoken', 'Symfony', $client ?? new MockHttpClient());
     }