explain implementation of ad-hoc depencency container

app/src/Action/Hello.php

@@ -2,7 +2,6 @@
 
 namespace Lubian\NoFramework\Action;
 
-
 use Lubian\NoFramework\Service\Time\Clock;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
@@ -13,8 +12,7 @@ final class Hello implements RequestHandlerInterface
     public function __construct(
         private readonly ResponseInterface $response,
         private readonly Clock $clock
-    )
-    {
+    ) {
     }
 
     public function handle(ServerRequestInterface $request): ResponseInterface
@@ -22,7 +20,8 @@ final class Hello implements RequestHandlerInterface
         $name = $request->getAttribute('name', 'Stranger');
         $body = $this->response->getBody();
 
-        $time = $this->clock->now()->format('H:i:s');
+        $time = $this->clock->now()
+            ->format('H:i:s');
 
         $body->write('Hello ' . $name . '!<br />');
         $body->write('The Time is: ' . $time);

app/src/Bootstrap.php

@@ -59,7 +59,7 @@ try {
     switch ($routeInfo[0]) {
         case Dispatcher::FOUND:
             $className = $routeInfo[1];
-            $handler = new $className($response);
+            $handler = $container->get($className);
             assert($handler instanceof RequestHandlerInterface);
             foreach ($routeInfo[2] as $attributeName => $attributeValue) {
                 $request = $request->withAttribute($attributeName, $attributeValue);

app/src/Service/Time/Clock.php

@@ -2,7 +2,9 @@
 
 namespace Lubian\NoFramework\Service\Time;
 
+use DateTimeImmutable;
+
 interface Clock
 {
-    public function now(): \DateTimeImmutable;
-}
+    public function now(): DateTimeImmutable;
+}

app/src/Service/Time/SystemClock.php

@@ -2,11 +2,12 @@
 
 namespace Lubian\NoFramework\Service\Time;
 
+use DateTimeImmutable;
+
 final class SystemClock implements Clock
 {
-    public function now(): \DateTimeImmutable
+    public function now(): DateTimeImmutable
     {
-        return new \DateTimeImmutable();
+        return new DateTimeImmutable;
     }
-
-}
+}