Improve doc block comment and tests

src/Cms/Collections.php

@@ -101,12 +101,12 @@ public function has(string $name): bool
     }
 
     /**
-    * Loads collection from php file in a
-    * given directory or from plugin extension.
-    *
-    * @param  string $name
-    * @return mixed
-    */
+     * Loads collection from php file in a
+     * given directory or from plugin extension.
+     *
+     * @param  string $name
+     * @return mixed
+     */
     public function load(string $name)
     {
         $kirby = App::instance();

tests/Cms/CollectionsTest.php

@@ -12,6 +12,7 @@ protected function _app()
             ]
         ]);
     }
+
     public function testGet()
     {
         $app        = $this->_app();
@@ -60,4 +61,11 @@ public function testLoad()
         $result = $app->collections()->load('nested/test');
         $this->assertEquals('a', $result());
     }
+
+    public function testLoadNested()
+    {
+        $app = $this->_app();
+        $result = $app->collections()->load('nested/test');
+        $this->assertEquals('a', $result());
+    }
 }