public static function invoke($type, $args)
{
if ($class = self::exists($type)) {
$generator = new $class();
} else {
die('could not find generator ' . $type);
}
if (empty($args)) {
self::printUsage($type);
return false;
} else {
return call_user_func_array(array($generator, 'start'), $args);
}
}