title: RxJava use Single data and return Completable
body: <p>I´m working with RxJava in Android, I´m trying to create a function that will call to an API using Retrofit, the point is that I want to process the API data in the ViewModel and emit to the View a Completable, to notify if the request was successful or not.</p>
  
  <p>I have thought about using a Subject and then into the subscribe function call to the Subject onComplete or onError, but I´m not sure if this is a good practice.</p>
  
  <p>What I want is something like this</p>
  
  <pre><code>fun apiCall(paramA:String):Completable{
          webservice.myApiCall(paramA).subscribe { t1, t2 -&gt;
              if (t1  != null){
                  handleData(t1)
              }else {
                  handleError(t2)
              }
          }
          //The Completable should be returned here
      }
  </code></pre>