如何在反应式窗体的formGroup中以编程方式选中多个复选框？

<form [formGroup]="myForm">
  <label>
    <input type="checkbox" formControlName="checkbox1"> Checkbox 1
  </label>
  <label>
    <input type="checkbox" formControlName="checkbox2"> Checkbox 2
  </label>
  <label>
    <input type="checkbox" formControlName="checkbox3"> Checkbox 3
  </label>
</form>

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from '@angular/forms';

@Component({
  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
})
export class MyComponentComponent implements OnInit {
  myForm: FormGroup;

  constructor(private formBuilder: FormBuilder) { }

  ngOnInit() {
    this.myForm = this.formBuilder.group({
      checkbox1: false,
      checkbox2: false,
      checkbox3: false
    });
  }
}

this.myForm.patchValue({
  checkbox1: true,
  checkbox2: true
});