fixup! test(cdk-experimental/listbox): add unit tests

Author: wagnermaciel

src/cdk-experimental/listbox/listbox.spec.ts

@@ -1,16 +1,9 @@
 import {Component, DebugElement, signal} from '@angular/core';
 import {CdkListbox, CdkOption} from './listbox';
-import {
-  ComponentFixture,
-  TestBed,
-  fakeAsync,
-  tick,
-  discardPeriodicTasks,
-} from '@angular/core/testing';
+import {ComponentFixture, TestBed, fakeAsync, tick} from '@angular/core/testing';
 import {By} from '@angular/platform-browser';
 import {BidiModule, Direction} from '@angular/cdk/bidi';
-import {provideFakeDirectionality} from '@angular/cdk/testing/private';
-import {runAccessibilityChecks} from '@angular/cdk/testing/private';
+import {provideFakeDirectionality, runAccessibilityChecks} from '@angular/cdk/testing/private';
 
 interface ModifierKeys {
   ctrlKey?: boolean;

src/cdk-experimental/listbox/listbox.ts

@@ -110,9 +110,6 @@ export class CdkListbox<V> {
   /** Whether the listbox has received focus yet. */
   private _hasFocused = signal(false);
 
-  /** Whether the options in the listbox have been initialized. */
-  private _isViewInitialized = signal(false);
-
   constructor() {
     afterRenderEffect(() => {
       if (typeof ngDevMode === 'undefined' || ngDevMode) {