Node.js 实时通信模块发送消息 5 次有 3 次失败

var Realtime = require('leancloud-realtime').Realtime;
var TextMessage = require('leancloud-realtime').TextMessage;

var ms = realtime.createIMClient('black');

var send = function (unid, nr) {
    console.log('send:',unid)
    ms.then(function (black) {
            return black.createConversation({
                members: [unid],
                name: 'black & ' + unid,
                unique: true,
            });
    }).then(function (conversation) {
//这里有输出语句的话就没反应，不会输出
        return conversation.send(new TextMessage(nr));
    }).then(function (message) {
        console.log('black & ' + unid, '发送成功！');
    }).catch(console.error);
}