title: rxjs 7 update - Subject - Expected 1 arguments, but got 0
body: <p>I updated rxjs from version 6.x.x to 7.x.x, but following error appeared:</p>
  <blockquote>
  <p>Error in src/app/app.component.ts (12:19)
  Expected 1 arguments, but got 0.</p>
  </blockquote>
  <p>when trying to <code>next</code> an empty value to the <code>Subject</code></p>
  <pre class="lang-js prettyprint-override"><code>destroy$ = new Subject();
  
  constructor() {
    this.destroy$.next(); // &lt;-- Expected 1 arguments, but got 0.
  }
  </code></pre>
  <p><a href="https://stackblitz.com/edit/angular-ivy-xhxbmy?file=src%2Fapp%2Fapp.component.ts" rel="noreferrer">Error stackblitz</a></p>