Change visibility on the add method to protected

Slim/App.php

@@ -47,9 +47,7 @@
 class App
 {
     use CallableResolverAwareTrait;
-    use MiddlewareAwareTrait {
-        add as addMiddleware;
-    }
+    use MiddlewareAwareTrait;
 
     /**
      * Current version

Slim/MiddlewareAwareTrait.php

@@ -53,7 +53,7 @@ trait MiddlewareAwareTrait
      * @throws RuntimeException         If middleware is added while the stack is dequeuing
      * @throws UnexpectedValueException If the middleware doesn't return an instance of \Psr\Http\Message\ResponseInterface
      */
-    public function add(callable $callable)
+    protected function addMiddleware(callable $callable)
     {
         if ($this->middlewareLock) {
             throw new RuntimeException('Middleware can’t be added once the stack is dequeuing');

Slim/Route.php

@@ -22,9 +22,7 @@
  */
 class Route extends Routable implements RouteInterface
 {
-    use MiddlewareAwareTrait {
-        add as addMiddleware;
-    }
+    use MiddlewareAwareTrait;
 
     /**
      * HTTP methods supported by this route

tests/Mocks/Stackable.php

@@ -33,4 +33,10 @@ public function testMiddlewareKernel(ServerRequestInterface $req, ResponseInterf
     {
         return $res->write('hello from testMiddlewareKernel');
     }
+
+    public function add($callable)
+    {
+        $this->addMiddleware($callable);
+        return $this;
+    }
 }