public static function get_cache_content() {
        if (!isset(self::$plugintypes)) {
            self::fill_all_caches();
        }

        $cache = array(
            'subsystems'        => self::$subsystems,
            'plugintypes'       => self::$plugintypes,
            'plugins'           => self::$plugins,
            'parents'           => self::$parents,
            'subplugins'        => self::$subplugins,
            'classmap'          => self::$classmap,
            'classmaprenames'   => self::$classmaprenames,
            'filemap'           => self::$filemap,
            'version'           => self::$version,
        );

        return '<?php
$cache = '.var_export($cache, true).';
';
    }