Merge remote-tracking branch 'origin/master'

README.md

@@ -17,7 +17,7 @@ and using the callback to call several methods on the redirect middleware to cha
 
 ```php
 $loop = Factory::create(); 
-$server = new Server(new MiddlewareRunner([
+$server = new Server([
     /** Other middleware */
     new PSR15Middleware(
         $loop, // The react/event-loop (required) 
@@ -36,7 +36,33 @@ $server = new Server(new MiddlewareRunner([
         }
     ),
     /** Other middleware */
-]));
+]);
+```
+
+# Grouped Usage
+
+When using more then one PSR-15 in a row the `GroupedPSR15Middleware` is more performing than using multiple `PSR15Middleware`. Consider the 
+following example where we add [`middlewares/cache`](https://github.com/middlewares/cache) for expires headers:
+
+```php
+$loop = Factory::create(); 
+$server = new Server([
+    /** Other middleware */
+    (new GroupedPSR15Middleware($loop))->withMiddleware( 
+        Redirect::class,
+        [
+            ['/old-url' => '/new-url']
+        ],
+        function ($redirectMiddleware) {
+            return $redirectMiddleware
+                ->permanent(false)
+                ->query(false)
+                ->method(['GET', 'POST'])
+            ;
+        }
+    )->withMiddleware(Expires::class),
+    /** Other middleware */
+]);
 ```
 
 # Warning

src/GroupedPSR15Middleware.php

@@ -27,17 +27,18 @@ public function __construct(LoopInterface $loop)
         $this->kernel = ReactKernel::create($loop);
     }
 
-    public function add(string $middleware, array $arguments = [], callable $func = null)
+    public function withMiddleware(string $middleware, array $arguments = [], callable $func = null)
     {
         if ($func === null) {
             $func = function ($middleware) {
                 return $middleware;
             };
         }
 
-        $this->middleware[] = $func(YieldingMiddlewareFactory::construct($middleware, $arguments));
+        $clone = clone $this;
+        $clone->middleware[] = $func(YieldingMiddlewareFactory::construct($middleware, $arguments));
 
-        return $this;
+        return $clone;
     }
 
     public function __invoke(ServerRequestInterface $request, callable $next): Promise\PromiseInterface