prepare for testing

phpstan.neon

@@ -1,4 +1,4 @@
 parameters:
-	level: 1
+	level: 2
 	paths:
 		- src

src/Container.php

@@ -16,6 +16,7 @@ class Container implements ContainerContract
      * @var array
      */
     private array $services = [];
+
     /**
      * The container's  instance.
      *
@@ -34,16 +35,16 @@ class Container implements ContainerContract
     public static function instance(): static
     {
 
-        if (is_null(static::$instance)) {
-            static::$instance = new static();
+        if (!isset(self::$instance)) {
+            self::$instance = new self();
         }
 
-        return static::$instance;
+        return self::$instance;
     }
 
     /**
      * @param string $id
-     * @param object $service
+     * @return object
      */
     public function get(string $id): object
     {
@@ -152,4 +153,8 @@ private function __construct()
     private function __clone(): void
     {
     }
+
+    private function __wakeup()
+    {
+    }
 }

src/Contracts/ContainerContract.php

@@ -11,20 +11,14 @@ interface ContainerContract
      *
      * @param string $id Identifier of the entry to look for.
      *
-     * @throws NotFoundExceptionInterface  No entry was found for **this** identifier.
-     * @throws ContainerExceptionInterface Error while retrieving the entry.
-     *
      * @return mixed Entry.
      */
     public function get(string $id): mixed;
 
     /**
      * Returns true if the container can return an entry for the given identifier.
      * Returns false otherwise.
-     *
-     * `has($id)` returning true does not mean that `get($id)` will not throw an exception.
-     * It does however mean that `get($id)` will not throw a `NotFoundExceptionInterface`.
-     *
+     **
      * @param string $id Identifier of the entry to look for.
      *
      * @return bool