title: Can I add attributes to 'window' object in Angular 7?
body: <p>Can I add any attribute to 'window' object in Angular? Some thing like:</p>
  
  <pre><code>window.attr = "my_value"
  </code></pre>
  
  <p>I try tu use the object windows bat have the error:</p>
  
  <blockquote>
    <p>Property 'attr' does not exist on type 'Window'.</p>
  </blockquote>