pimcore/pimcore

Hi there,
I was trying to override a DataObject class (as documented in https://pimcore.com/docs/pimcore/current/Development_Documentation/Extending_Pimcore/Overriding_Models.html)
My config.yaml looks like this:

`

pimcore:
    models:
        class_overrides:
            'Pimcore\Model\DataObject\BlogEntry': 'App\Model\DataObject\BlogEntry'

`

and the App\Model\DataObject\BlogEntry class looks like this:

`

<?php 

namespace App\Model\DataObject; 

use Pimcore\Model\DataObject\BlogEntry\Listing as BlogEntryListing;

class BlogEntry extends \Pimcore\Model\DataObject\BlogEntry {

    private function setShowOnHomepageParent(?bool $showOnHomepage)
    {
        parent::setShowOnHomepage($showOnHomepage);
    }

    /**
    * Set showOnHomepage
    * @param bool|null $showOnHomepage
    * @return \App\Model\DataObject\BlogEntry
    */
    // this method already exists and is meant to be overriden
    public function setShowOnHomepage(?bool $showOnHomepage)
    {
        if ( $showOnHomepage == true ) {
            // Get all blog entries that are not the current object
            $temp_blog_entry_listing = new BlogEntryListing();
            $temp_blog_entry_listing2->setCondition("id != ?", $this->getId());
            $temp_blog_entry_listing->load();

            // Set showOnHomepage to false on all those blog entries
            foreach ( $temp_blog_entry_listing as $key => $blog_entry ) {
                $blog_entry->setShowOnHomepageParent(false);
            }
        }

        $this->setShowOnHomepageParent($showOnHomepage);

        return $this;
    }
}

`

Unfortunately when adding a new blogEntry object (in the admin panel via DataObjects) I get the following error message:
Attempted to load class "BlogEntry" from namespace "App\Model\DataObject". Did you forget a "use" statement for "Pimcore\Model\DataObject\BlogEntry"?
Server threw exception - could not perform action. Please reload the admin interface and try again.

What am I doing wrong?