CBPHelper::convertToExtendedGroups

static function convertToExtendedGroups($users)
{
	$users = (array)$users;
	foreach ($users as &$user)
	{
		if (!is_scalar($user))
			continue;
		$user = (string) $user;
		if (mb_strpos($user, 'user_') === 0)
		{
			$user = 'group_u'.mb_substr($user, mb_strlen('user_'));
		}
		elseif (preg_match('#^[0-9]+$#', $user))
		{
			$user = 'group_g'.$user;
		}
		else
			$user = mb_strtolower($user);
	}
	return $users;
}