diff --git a/README.md b/README.md
index c5239e1..3d9ab17 100644
--- a/README.md
+++ b/README.md
@@ -55,7 +55,7 @@
 To retrieve a service from the container, use the `get` method:
 
 ```php
-$myService = $container->get('myService');
+$myService = $container->get(MyService::class);
 ```
 
 ### Invoking Methods
@@ -75,7 +75,10 @@
 #### Methods
 
 - `__construct(array $definitions = [])`: Creates a new container with optional initial service definitions.
+- `value(string $name, mixed $value): self`: Define a value to be stored in the container.
+- `alias(string $name, string $alias): self`: Define an alias for a name in the container.
 - `set(string $name, string|callable $value, array $constants = [], bool $singleton = false): self`: Defines a service in the container.
+- `has(string $id): bool`: Returns true if the container can return an entry for the given identifier.
 - `get(string $id): mixed`: Retrieves a service from the container.
 - `invoke(string|object $entry, string $method = '__invoke', array $constants = []): mixed`: Invokes a method on an object.
 
diff --git a/composer.json b/composer.json
index 9b4d8c6..4a40ad7 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
     "name": "uid/lib-di-container",
     "type": "library",
-    "description": "simple implementation of PSR-11: Container",
+    "description": "A simple implementation of PSR-11: Container.",
     "keywords": ["psr-11", "di", "container"],
     "license": "Apache-2.0",
     "autoload": {
diff --git a/src/Container/Container.php b/src/Container/Container.php
index 624bf77..a27dfee 100644
--- a/src/Container/Container.php
+++ b/src/Container/Container.php
@@ -11,11 +11,9 @@
 use function array_key_exists;
 use function array_map;
 use function class_exists;
-use function class_implements;
-use function class_parents;
 use function count;
 use function get_class;
-use function in_array;
+use function is_a;
 use function is_object;
 use function is_string;
 use function method_exists;
@@ -44,7 +42,7 @@
      * @param mixed $value The value to store.
      * @return Container The container instance.
      */
-    public function value(string $name, $value): self
+    public function value(string $name, mixed $value): self
     {
         $this->definitions[$name] = ['value' => $value];
         return $this;
@@ -108,7 +106,9 @@
     /** @inheritdoc*/
     public function has(string $id): bool
     {
-        return $this->definition($this->resolve($id)) !== null;
+        //return $this->definition($this->resolve($id)) !== null;
+        $name = $this->resolve($id);
+        return array_key_exists($name, $this->definitions) || class_exists($name);
     }
     /** @inheritdoc*/
     public function get(string $id): mixed
@@ -142,8 +142,14 @@
         } catch (ReflectionException $ex) {
             throw new ContainerException(sprintf("Unable to invoke method '%s' for instance of '%s'", $method, get_class($object)), 0, $ex);
         }
-        $arguments = array_map(fn($parameter) => $this->argument($parameter, $constants), $reflection->getParameters());
-        return $object->$method(... array_map(fn($arg) => $arg[0] ? $this->get($arg[1]): $arg[1], $arguments));
+        $arguments = array_map(
+                fn($parameter) => $this->argument($parameter, $constants), 
+                $reflection->getParameters()
+        );
+        return $object->$method(... array_map(
+                fn($arg) => $arg[0] ? $this->get($arg[1]): $arg[1], 
+                $arguments
+        ));
     }
     /**
      * Get the definition for the given entry name.
@@ -195,9 +201,15 @@
         }
         $arguments = [];
         if (($constructor = $reflection->getConstructor())) {
-            $arguments = array_map(fn($parameter) => $this->argument($parameter, $constants), $constructor->getParameters());
+            $arguments = array_map(
+                    fn($parameter) => $this->argument($parameter, $constants), 
+                    $constructor->getParameters()
+            );
         }
-        return fn(Container $container) => new $class(... array_map(fn($arg) => $arg[0] ? $container->get($arg[1]) : $arg[1], $arguments));
+        return fn(Container $container) => new $class(... array_map(
+                fn($arg) => $arg[0] ? $container->get($arg[1]) : $arg[1],
+                $arguments
+        ));
     }
     /**
      * Create a callback for the given callable.
@@ -217,11 +229,17 @@
         if (empty($parameters)) {
             return $callback;
         }
-        if (count($parameters) === 1 && self::isImplements($parameters[0]->getType(), self::class)) {
+        if (count($parameters) === 1 && is_a($this, $parameters[0]->getType())) {
             return $callback;
         }
-        $arguments = array_map(fn($parameter) => $this->argument($parameter, $constants), $parameters);
-        return fn(Container $container) => $callback(... array_map(fn($arg) => $arg[0] ? $container->get($arg[1]): $arg[1], $arguments));
+        $arguments = array_map(
+                fn($parameter) => $this->argument($parameter, $constants), 
+                $parameters
+        );
+        return fn(Container $container) => $callback(... array_map(
+                fn($arg) => $arg[0] ? $container->get($arg[1]): $arg[1],
+                $arguments
+        ));
     }
     /**
      * Resolve the argument for a parameter.
@@ -243,11 +261,4 @@
         }
         throw new ContainerException(sprintf("Failed to process a parameter: '%s' of type '%s'", $name, $type));
     }
-    
-    private static function isImplements(string $type, string $class): bool
-    {
-        return $type == $class 
-                || in_array($type, class_parents($class))
-                || in_array($type, class_implements($class));
-    }
 }
diff --git a/tests/Container/ContainerTest.php b/tests/Container/ContainerTest.php
index af4e6d4..2ff5fac 100644
--- a/tests/Container/ContainerTest.php
+++ b/tests/Container/ContainerTest.php
@@ -49,11 +49,13 @@
         $container = (new Container())
                 ->factory(ContainerTest::class, fn() => new ContainerTest(), [], true)
                 ->factory('Service1', fn(ContainerInterface $container) => $container->get(ContainerTest::class))
-                ->factory('Service2', fn(ContainerTest $class) => $class);
+                ->factory('Service2', fn(ContainerTest $class) => $class)
+                ->factory('Service3', fn(Container $class) => $class);
 
         $this->assertInstanceOf(ContainerTest::class, $container->get(ContainerTest::class));
         $this->assertInstanceOf(ContainerTest::class, $container->get('Service1'));
         $this->assertInstanceOf(ContainerTest::class, $container->get('Service2'));
+        $this->assertInstanceOf(Container::class, $container->get('Service3'));
     }
     
     public function testSingleton()