title: How to dispatch an empty action?
body: <p>I am using <a href="https://github.com/ngrx/effects" rel="noreferrer">ngrx/effects</a>.</p>
  
  <p>How can I dispatch an empty action?</p>
  
  <p>This is how I am doing now:</p>
  
  <pre><code> @Effect() foo$ = this.actions$
      .ofType(Actions.FOO)
      .withLatestFrom(this.store, (action, state) =&gt; ({ action, state }))
      .map(({ action, state }) =&gt; {
        if (state.foo.isCool) {
          return { type: Actions.BAR };
        } else {
          return { type: 'NOT_EXIST' };
        }
      });
  </code></pre>
  
  <p>Since I have to return an action, I am using <code>return { type: 'NOT_EXIST' };</code>.</p>
  
  <p>Is there a better way to do this? </p>