TreeSelect: 'itemcheckboxicon' issue

[ghost]

Describe the bug

When using the <p-treeSelect> component, we can customize the style of the checkboxes by setting the itemcheckboxicon template. However, we are unable to set the style for the partially selected state by accessing partialSelected.

<p-treeSelect class="w-full md:w-20rem" containerStyleClass="w-full" [(ngModel)]="selectedNodes" [options]="nodes" display="chip" [metaKeySelection]="false" selectionMode="checkbox" placeholder="Select Item">
  <ng-template let-partialSelected="partialSelected" pTemplate="itemcheckboxicon">
    <div [class]="partialSelected ? 'my-checkbox-minus-icon' : 'my-checkbox-icon'"></div>
  </ng-template>
</p-treeSelect>

Environment

Windows 10, Chrome

Reproducer

No response

Angular version

15.2.1

PrimeNG version

15.4.1

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

v16.14.0

Browser(s)

No response

Steps to reproduce the behavior

No response

Expected behavior

No response