private static function environment() {
	$environment = getenv('APP_ENV') ?: 'production';
	
	define('alsvanzelf\fem\ENVIRONMENT',  $environment);
	define('alsvanzelf\fem\ROOT_DIR',     realpath(__DIR__.'/../../../../').'/');
	define('alsvanzelf\fem\ROOT_DIR_APP', \alsvanzelf\fem\ROOT_DIR.'application/');
	define('alsvanzelf\fem\CLI',          (strpos(php_sapi_name(), 'cli') !== false || defined('STDIN')));
	
	if (constant('\alsvanzelf\fem\ENVIRONMENT') == false) {
		echo 'no environment set';
		exit;
	}
}