title: what is the alternative for the util.isNullOrUndefined(object) in the Util module ? Angular 7
body: <p>util.isNullOrUndefined(object) has been depreciated and I cannot find any alternative for it. Can someone point out a feasible alternative for it?</p>
  
  <pre><code>if (isNullOrUndefined(this.activeAppKey) || this.activeAppKey.trim().length === 0) {
    this.activeAppKey = sessionStorage.getItem(AppConstants.APP_KEY);
  }
  </code></pre>