Merge branch '4.4' into 5.1

* 4.4:
  Use ::class keyword when possible

Author: fabpot

Tests/HttpBrowserTest.php

@@ -73,7 +73,7 @@ public function testMultiPartRequestWithSingleFile()
             ->method('request')
             ->with('POST', 'http://example.com/', $this->callback(function ($options) {
                 $this->assertStringContainsString('Content-Type: multipart/form-data', implode('', $options['headers']));
-                $this->assertInstanceOf('\Generator', $options['body']);
+                $this->assertInstanceOf(\Generator::class, $options['body']);
                 $this->assertStringContainsString('my_file', implode('', iterator_to_array($options['body'])));
 
                 return true;
@@ -183,7 +183,7 @@ protected function expectClientToSendRequestWithFiles(HttpClientInterface $clien
             ->method('request')
             ->with('POST', 'http://example.com/', $this->callback(function ($options) use ($fileContents) {
                 $this->assertStringContainsString('Content-Type: multipart/form-data', implode('', $options['headers']));
-                $this->assertInstanceOf('\Generator', $options['body']);
+                $this->assertInstanceOf(\Generator::class, $options['body']);
                 $body = implode('', iterator_to_array($options['body'], false));
                 foreach ($fileContents as $content) {
                     $this->assertStringContainsString($content, $body);
@@ -201,7 +201,7 @@ protected function expectClientToNotSendRequestWithFiles(HttpClientInterface $cl
             ->method('request')
             ->with('POST', 'http://example.com/', $this->callback(function ($options) use ($fileContents) {
                 $this->assertStringContainsString('Content-Type: multipart/form-data', implode('', $options['headers']));
-                $this->assertInstanceOf('\Generator', $options['body']);
+                $this->assertInstanceOf(\Generator::class, $options['body']);
                 $body = implode('', iterator_to_array($options['body'], false));
                 foreach ($fileContents as $content) {
                     $this->assertStringNotContainsString($content, $body);