clr-angular-static-fix/layout/vertical-nav/vertical-nav-group.html

1. Install Clarity Icons package through npm:

<!--
  ~ Copyright (c) 2016-2018 VMware, Inc. All Rights Reserved.
  ~ This software is released under MIT license.
  ~ The full license information can be found in LICENSE in the root directory of this project.
  -->

<div class="nav-group-content">
    <ng-content select="[clrVerticalNavLink]"></ng-content>
    <button
        class="nav-group-trigger"
        type="button"
        (click)="toggleExpand()">
        <ng-content select="[clrVerticalNavIcon]"></ng-content>
        <div class="nav-group-text">
            <ng-content></ng-content>
        </div>
        <clr-icon shape="caret"
                  class="nav-group-trigger-icon"
                  [attr.dir]="(this.expanded) ? 'down' : 'right'">
        </clr-icon>
    </button>
</div>
<!--TODO: This animation needs to be added to the clr-vertical-nav-group-children component-->
<div class="nav-group-children"
     [@clrExpand]="expandAnimationState"
     (@clrExpand.done)="expandAnimationDone($event)">
    <ng-content select="[clrIfExpanded], clr-vertical-nav-group-children"></ng-content>
</div>