angular - NgZone/Angular2/Ionic2 TypeError: 未定義のプロパティ 'run' を読み取れません

Question

このエラーTypeError: Cannot read property 'run' of undefined in Subscriber.js:229が発生 し、理由がわかりません - ionic beta 10 では、このコードは正常に動作します... 11 では動作しません。

import {Component, NgZone} from '@angular/core';
import {NavController} from 'ionic-angular';

declare var io;

@Component({
  templateUrl: 'build/pages/home/home.html'
})    
export class HomePage {
    static get parameters() {
        return [NgZone];
    }

    zone: any;
    chats: any;
    chatinp: any;
    socket: any;

constructor(public navCtrl: NavController, ngzone) {
    this.zone = ngzone;
    this.chats = [];
    this.chatinp ='';
    this.socket = io('http://localhost:3000');
    this.socket.on('message', (msg) => {
        this.zone.run(() => {
            this.chats.push(msg);
        });
    });
}

send(msg) {
    if(msg != ''){
        this.socket.emit('message', msg);
    }
    this.chatinp = '';
   }
}