import { Component, OnInit, Output, Input, EventEmitter } from ‘@angular/core‘;@Component({    selector: ‘twoway‘,    template: `       <input [(ngModel)]="username">       <p>Hello {{username}}!</p>    `})export class TwoWayComponent implements OnInit {    constructor() { }    usernameValue: string;    @Output() usernameChange = new EventEmitter();    @Input()    get username() {        return this.usernameValue;    }    set username(val) {        this.usernameValue =http://www.mamicode.com/ val;        this.usernameChange.emit(this.usernameValue);    }    ngOnInit() {    }}