Jetpack::is_development_mode PHP Method

    public static function is_development_mode()
    {
        $development_mode = false;
        if (defined('JETPACK_DEV_DEBUG')) {
            $development_mode = JETPACK_DEV_DEBUG;
        } elseif (site_url() && false === strpos(site_url(), '.')) {
            $development_mode = true;
        }
        /**
         * Filters Jetpack's development mode.
         *
         * @see https://jetpack.com/support/development-mode/
         *
         * @since 2.2.1
         *
         * @param bool $development_mode Is Jetpack's development mode active.
         */
        return apply_filters('jetpack_development_mode', $development_mode);
    }

 function page_render()
 {
     // Handle redirects to configuration pages
     if (!empty($_GET['configure'])) {
         return $this->render_nojs_configurable();
     }
     global $current_user;
     $is_connected = Jetpack::is_active();
     $user_token = Jetpack_Data::get_access_token($current_user->ID);
     $is_user_connected = $user_token && !is_wp_error($user_token);
     $is_master_user = $current_user->ID == Jetpack_Options::get_option('master_user');
     if (Jetpack::is_development_mode()) {
         $is_connected = true;
         $is_user_connected = true;
         $is_master_user = false;
     }
     // Set template data for the admin page template
     $data = array('is_connected' => $is_connected, 'is_user_connected' => $is_user_connected, 'is_master_user' => $is_master_user);
     Jetpack::init()->load_view('admin/admin-page.php', $data);
 }