public function addTag($id, $tag, $fromAdminId = null, $botName = 'Bot', $randomId = 0)
    {
        if ($this->isEmptyId($id)) {
            throw new InvalidArgumentException;
        }

        if (!$tag) {
            throw new InvalidArgumentException;
        }

        $tag = str_replace(',', '', $tag);

        $params = [
            'action' => 'add',
            'tag' => $tag
        ];

        $fromAdminId = (int)$fromAdminId;
        if ($fromAdminId) {
            $params['from_admin'] = $fromAdminId;
        } else {
            $params['bot_name'] = $botName;
        }

        $randomId = (int)$randomId;
        if ($randomId) {
            $params['random_id'] = $randomId;
        }

        $res = $this->call('conversations/' . $id . '/tag', $params, 'post');

        if ($res) {
            return true;
        }

        return false;
    }