public static function sendMessage($chat_id = null, $text, $inline_keyboard = '', $reply_keyboard = '', $parse_mode = 'HTML', $disable_web_page_preview = false, $disable_notification = false, $reply_to_message_id = '')
    {
        self::initialize();
        $chat_id = $chat_id ? $chat_id : self::$channel_username;
        $params = compact('chat_id','text', 'parse_mode', 'disable_web_page_preview', 'disable_notification', 'reply_to_message_id');
        if($inline_keyboard) {
            $params['reply_markup'] = self::inlineKeyboard($inline_keyboard);
        }
        if($reply_keyboard) {
            $params['reply_markup'] = self::replyKeyboard($reply_keyboard);
        }
        $result = self::sendRequest('sendMessage', $params);
        return $result? $result : false;
    }