remove dead code, fixes #1241

Closes #1241

Merge request studip/studip!756

lib/classes/ContentBoxHelper.php

 <?php
 /**
  * ContentBoxHelper.php
- * 
+ *
  * The ContentBoxHelper controls ids of contentboxes
  *
  * This program is free software; you can redistribute it and/or
@@ -19,33 +19,33 @@ class ContentBoxHelper {
 
     /**
      * Returns the class open if the id was clicked
-     * 
+     *
      * @param String $id id of the content box
      * @param int $chdate last change of the displayed article
-     * @return String open if the contentbox is open otherwise an empty String 
+     * @return String open if the contentbox is open otherwise an empty String
      */
     public static function classes($id, $is_new = false) {
-        
+
         // Init
         $classes = [];
-        
+
         // Check if open
         if (Request::get('contentbox_open') == $id) {
             $classes[] = 'open';
         }
-        
+
         // Check if new
         if ($is_new) {
             $classes[] = 'new';
         }
-        
+
         // Return classes
         return join(' ', $classes);
     }
 
     /**
      * Produces an html link to open a contentbox if javascript is not active
-     * 
+     *
      * @param String $id Id of the content box
      * @param Array $params other needed parameters
      * @return String Url to open the contentbox
@@ -61,7 +61,7 @@ class ContentBoxHelper {
 
     /**
      * Link to the contentbox (Required when some action should take place)
-     * 
+     *
      * @param String $id Id of the content box
      * @param Array $params other needed parameters
      * @return String Url to the contentbox
@@ -70,18 +70,4 @@ class ContentBoxHelper {
         $params['contentbox_open'] = $id;
         return URLHelper::getURL("#$id", $params);
     }
-    
-    /**
-     * Sets an object as visited
-     * 
-     * @param String $type the type to be set in the database
-     * @param Array $ids Array of ids that might be visited with the given type
-     */
-    public static function visitType($type, $ids) {
-        $object_id = Request::get('contentbox_open');
-        if ($object_id && in_array($object_id, $ids)) {
-            ObjectVisit::visit($object_id, $type);
-        }
-    }
-
 }