diff --git a/src/Handler/ContainerHandler.php b/src/Handler/ContainerHandler.php
index 849e300..e750deb 100644
--- a/src/Handler/ContainerHandler.php
+++ b/src/Handler/ContainerHandler.php
@@ -35,10 +35,7 @@ class ContainerHandler implements AfterMethodCallAnalysisInterface, AfterClassLi
         'Symfony\Bundle\FrameworkBundle\Test\TestContainer',
     ];
 
-    /**
-     * @var ContainerMeta|null
-     */
-    private static $containerMeta;
+    private static ?ContainerMeta $containerMeta = null;
 
     /**
      * @var array<string> collection of cower-cased class names that are present in the container
@@ -114,7 +111,7 @@ public static function afterMethodCallAnalysis(AfterMethodCallAnalysisEvent $eve
             } else {
                 try {
                     $serviceId = \constant($className.'::'.$idArgument->name->name);
-                } catch (\Exception $e) {
+                } catch (\Exception) {
                     return;
                 }
             }
@@ -133,7 +130,7 @@ public static function afterMethodCallAnalysis(AfterMethodCallAnalysisEvent $eve
             }
 
             $class = $service->getClass();
-            if ($class) {
+            if (null !== $class) {
                 $codebase->classlikes->addFullyQualifiedClassName($class);
                 $event->setReturnTypeCandidate(new Union([new TNamedObject($class)]));
             }
@@ -152,7 +149,7 @@ public static function afterMethodCallAnalysis(AfterMethodCallAnalysisEvent $eve
                     );
                 }
             }
-        } catch (ServiceNotFoundException $e) {
+        } catch (ServiceNotFoundException) {
             IssueBuffer::accepts(
                 new ServiceNotFound($serviceId, new CodeLocation($statements_source, $firstArg->value)),
                 $statements_source->getSuppressedIssues()
@@ -160,7 +157,7 @@ public static function afterMethodCallAnalysis(AfterMethodCallAnalysisEvent $eve
         }
     }
 
-    public static function afterClassLikeVisit(AfterClassLikeVisitEvent $event)
+    public static function afterClassLikeVisit(AfterClassLikeVisitEvent $event): void
     {
         $codebase = $event->getCodebase();
         $statements_source = $event->getStatementsSource();
@@ -221,7 +218,7 @@ function ($c) use ($methodName) {
 
     private static function followsParameterNamingConvention(string $name): bool
     {
-        if (0 === strpos($name, 'env(')) {
+        if (str_starts_with($name, 'env(')) {
             return true;
         }
 
diff --git a/src/Symfony/ContainerMeta.php b/src/Symfony/ContainerMeta.php
index e055ac8..e7d86bb 100644
--- a/src/Symfony/ContainerMeta.php
+++ b/src/Symfony/ContainerMeta.php
@@ -19,22 +19,19 @@ class ContainerMeta
     /**
      * @var array<string>
      */
-    private $classNames = [];
+    private array $classNames = [];
 
     /**
      * @var array<string, string>
      */
-    private $classLocators = [];
+    private array $classLocators = [];
 
     /**
      * @var array<string, array<string, string>>
      */
-    private $serviceLocators = [];
+    private array $serviceLocators = [];
 
-    /**
-     * @var ContainerBuilder
-     */
-    private $container;
+    private ContainerBuilder $container;
 
     public function __construct(array $containerXmlPaths)
     {
@@ -67,10 +64,7 @@ public function get(string $id, ?string $contextClass = null): Definition
         return $definition;
     }
 
-    /**
-     * @return mixed|null
-     */
-    public function getParameter(string $key)
+    public function getParameter(string $key): mixed
     {
         return $this->container->getParameter($key);
     }
@@ -111,7 +105,7 @@ private function init(array $containerXmlPaths): void
                 $this->classLocators[$this->container->getDefinition($id)->getClass() ?? $id] = (string) $reference;
             } elseif ($definition->hasTag('container.service_locator')) {
                 continue;
-            } elseif ($className = $definition->getClass()) {
+            } elseif (null !== $className = $definition->getClass()) {
                 $this->classNames[] = $className;
             }
         }
@@ -138,10 +132,10 @@ private function addServiceLocator(string $key, string $id, Reference $reference
         try {
             $definition = $this->getDefinition((string) $reference);
             $className = $definition->getClass();
-            if ($className) {
+            if (null !== $className) {
                 $this->classNames[] = $className;
             }
-        } catch (ServiceNotFoundException $e) {
+        } catch (ServiceNotFoundException) {
         }
     }
 
@@ -155,7 +149,7 @@ private function getDefinition(string $id): Definition
         } catch (ServiceNotFoundException $serviceNotFoundException) {
             try {
                 $alias = $this->container->getAlias($id);
-            } catch (InvalidArgumentException $e) {
+            } catch (InvalidArgumentException) {
                 throw $serviceNotFoundException;
             }