class TP_Admin
{
    public function __construct()
    {
        add_action('admin_menu', [$this, 'registerMenus']);
    }

    public function registerMenus()
    {
        add_menu_page(
            'Training',
            'Training',
            'manage_options',
            'tp-dashboard',
            [$this, 'dashboardPage'],
            'dashicons-chart-line',
            26
        );

        add_submenu_page(
            'tp-dashboard',
            'Übungen',
            'Übungen',
            'manage_options',
            'tp-exercises',
            ['TP_Admin_Exercises', 'listPage']
        );

        add_submenu_page(
            'tp-dashboard',
            'Neue Übung',
            'Neue Übung',
            'manage_options',
            'tp-exercise-new',
            ['TP_Admin_Exercises', 'editPage']
        );

        add_submenu_page(
            'tp-dashboard',
            'Ergebnisse',
            'Ergebnisse',
            'manage_options',
            'tp-results',
            ['TP_Admin_Results', 'listPage']
        );

        add_submenu_page(
            'tp-dashboard',
            'Einstellungen',
            'Einstellungen',
            'manage_options',
            'tp-settings',
            ['TP_Admin_Settings', 'page']
        );
    }

    public function dashboardPage()
    {
        echo "<div class='wrap'>";
        echo "<h1>Training Plugin</h1>";
        echo "<p>Willkommen.</p>";
        echo "</div>";
    }
}{"id":1,"name":"admin","url":"https:\/\/billard.herbord.de","description":"","link":"https:\/\/billard.herbord.de\/?author=1","slug":"cc_herbord","avatar_urls":{"24":"https:\/\/secure.gravatar.com\/avatar\/b9608a95f73811dfcdc7857ad63a5cf3372f514dcc0fa045a419a80538ae696e?s=24&d=mm&r=g","48":"https:\/\/secure.gravatar.com\/avatar\/b9608a95f73811dfcdc7857ad63a5cf3372f514dcc0fa045a419a80538ae696e?s=48&d=mm&r=g","96":"https:\/\/secure.gravatar.com\/avatar\/b9608a95f73811dfcdc7857ad63a5cf3372f514dcc0fa045a419a80538ae696e?s=96&d=mm&r=g"},"meta":[],"_links":{"self":[{"href":"https:\/\/billard.herbord.de\/index.php?rest_route=\/wp\/v2\/users\/1","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/billard.herbord.de\/index.php?rest_route=\/wp\/v2\/users"}]}}