ng-zorro中tree点击后取消的key值问题

Question

html

<nz-tree #nzTreeComponent *ngIf="testTree.length>0" [nzData]="testTree" nzCheckable [nzCheckedKeys]="defaultCheckedKeys"
        [nzExpandedKeys]="defaultExpandedKeys" (nzCheckBoxChange)="nzCheck($event)">
      </nz-tree> 

ts

// 点击复选框触发
  nzCheck(event: NzFormatEmitEvent): void {
    this.testfuncAllIDtest = event.checkedKeys;
    this.testfuncAllIDtest.forEach((element) => {
      if (element._children.length != 0) {
        var i = element._children;
        i.forEach((element) => {
          var y = element.key;
          this.funcAllIDtest.push(y);
        });
      } 
      else {
        this.funcAllIDtest.push(element.key);
      }
      console.log(new Set(this.funcAllIDtest));
    });
  }

但是会存在一个问题，当取消勾选后，复选框的值还是存在，如何避免这个情况？