Replace get_class() calls by ::class

Author: deguif

HttpClient/Test/HttpClientTestCase.php

@@ -1125,7 +1125,7 @@ public function testWithOptions()
         $client2 = $client->withOptions(['base_uri' => 'http://localhost:8057/']);
 
         $this->assertNotSame($client, $client2);
-        $this->assertSame(\get_class($client), \get_class($client2));
+        $this->assertSame($client::class, $client2::class);
 
         $response = $client2->request('GET', '/');
         $this->assertSame(200, $response->getStatusCode());