Dialog::hasAccess

static function hasAccess($dialogId, $userId = null)
{
	$userId = BitrixImCommon::getUserId($userId);
	if (!$userId)
	{
		return false;
	}

	if (BitrixImCommon::isChatId($dialogId))
	{
		$chatId = self::getChatId($dialogId, $userId);

		return BitrixImV2Chat::getInstance($chatId)->hasAccess($userId);
	}

	return BitrixImV2EntityUserUser::getInstance($dialogId)->hasAccess($userId);
}