How to display selected checkbox count in Angular2-multiselect?

I want to print that '5 items selected' on multiselect dropdown. here I attach an image of multiselect dropdown. I have used the angular2-multiselect dropdown npm package.

https://i.stack.imgur.com/Zqo4e.png

here is my html code:

  <angular2-multiselect [data]="itemList" [(ngModel)]="selectedItems" [settings]="settings"
    (onSelect)="onItemSelect($event)" (onDeSelect)="OnItemDeSelect($event)" (onSelectAll)="onSelectAll($event)"
    (onDeSelectAll)="onDeSelectAll($event)" formControlName="skills">
  </angular2-multiselect>

here is my configuration settings.

this.settings = {
      text: "Select Skills",
      selectAllText: 'Select All',
      unSelectAllText: 'UnSelect All',
      badgeShowLimit: 2,   
    };