title: How do I get a service from the container directly, if I didn't/couldn't inject the service using DI?
body: <p>I have a part of code where I'm injecting two services <code>$checker</code> and <code>$paginator</code> by dependency injection. It works perfectly:</p>
  
  <pre><code>public function index(Request $request, Paginator $paginator, Checker $checker)
      {
          $result = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];
          $partialResult = $paginator-&gt;getPartial($result, 0, 3);
          $checker-&gt;isValid('A');
          var_dump("test");
          die;
      }
  </code></pre>
  
  <p>Below the configuration on <code>services.yaml</code> file:</p>
  
  <pre><code>   paginator:
          public: true
          class: 'App\Helper\Paginator'
  
      checker:
          public: true
          class: 'App\Helper\Checker'
          arguments:
           $paginator: '@paginator'
  </code></pre>
  
  <p>But I'd like to inject for some reasons service by method:</p>
  
  <pre><code>$checker = $this-&gt;container-&gt;get('checker');
  </code></pre>
  
  <p>But it doesn't work. In previous versions Symfony like 3.4 it used to.</p>
  
  <p>I'm receiving an error:</p>
  
  <blockquote>
    <p>Service "checker" not found: event though it exists in the app's container, the container inside "App\Controller\DefaultController" is a smaller service locator that only knows about the "http_kernel", "parameter_bag", "request_stack", "router", "session", and "twig" services. Try using dependency injection instead.</p>
  </blockquote>
  
  <p>How should I solve this? </p>