title: CompletableObserver No Suitable Method Found
body: <p>Still a little new to RxJava and trying to implement a method that returns a Completable:</p>
  
  <p>Here is the retrofit class:</p>
  
  <pre><code>@GET
  Completable fetchSomething(@Url String url);
  </code></pre>
  
  <p>And here is where I am calling that method:</p>
  
  <pre><code>myRetrofit.fetchSomething(url)
      .subscribe(new CompletableObserver() {
          @Override
          public void onSubscribe(Disposable d) {
  
          }
  
          @Override
          public void onComplete() {
  
          }
  
          @Override
          public void onError(Throwable e) {
  
          }
      });
  }
  </code></pre>
  
  <p>Seems pretty straightforward, but the body of the CompletableObserver won't compile. I get this error:</p>
  
  <blockquote>
    <p>error: no suitable method found for subscribe(anonymous CompletableObserver)<br> 
    method Completable.subscribe(Action0) is not
    applicable<br>(argument mismatch; anonymous CompletableObserver cannot
    be converted to Action0)<br> method
    Completable.subscribe(CompletableSubscriber) is not applicable<br>
    (argument mismatch; anonymous CompletableObserver cannot be
    converted to CompletableSubscriber)<br>method
    Completable.subscribe(Subscriber) is not applicable<br>(cannot
    infer type-variable(s) T<br>(argument mismatch; anonymous
    CompletableObserver cannot be converted to Subscriber T ))<br>where T is
    a type-variable:<br>T extends Object declared in method
    T subscribe(Subscriber T)</p>
  </blockquote>
  
  <p>Thanks for any advice.</p>