minor #8530 Updated bootKernel examples to return the $kernel object (javiereguiluz)

This PR was merged into the 3.3 branch.

Discussion
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Updated bootKernel examples to return the $kernel object

This fixes #7783.

Commits
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8c168eb Updated bootKernel examples to return the $kernel object

Author: xabbuh

console.rst

@@ -224,8 +224,8 @@ console::
     {
         public function testExecute()
         {
-            self::bootKernel();
-            $application = new Application(self::$kernel);
+            $kernel = self::bootKernel();
+            $application = new Application($kernel);
 
             $application->add(new CreateUserCommand());
 

testing/doctrine.rst

@@ -36,9 +36,9 @@ which makes all of this quite easy::
          */
         protected function setUp()
         {
-            self::bootKernel();
+            $kernel = self::bootKernel();
 
-            $this->em = static::$kernel->getContainer()
+            $this->em = $kernel->getContainer()
                 ->get('doctrine')
                 ->getManager();
         }