title: RXJava - concat doesn't works
body: <p>I've a problem using RXJava and Kotlin.</p>
  
  <p>I'm using LiveData and Rx, my problem is that concat method is not concatenating two arrays that I have in Dummy data.</p>
  
  <p><strong>This is my code:</strong></p>
  
  <pre><code> disposables.
                  add(
                  Observable.concat(Observable.just(DummyContent.COMPANIES),
                          Observable.just(DummyContent.COMPANIES))
                  .subscribeOn(Schedulers.io())
                  .observeOn(AndroidSchedulers.mainThread())
                  .subscribe({
                      Timber.d("get companies success ${it.size}" )
                      companiesLiveData.value = it
                  },{
                       t -&gt; Timber.e(t, "get companies error")
                  }))
  </code></pre>
  
  <p>DummyContent:</p>
  
  <pre><code> val COMPANIES: MutableList&lt;Company&gt; = ArrayList()
    ...
     // Add some sample items.
          for (i in 1..4) {
              addCompany(createDummyCompany(i))
          }
  </code></pre>
  
  <p>When I run the code, I only see 4 elements in the list, I was expecting to receive 4  +  4  = 8 items because the <code>concat</code> method.</p>
  
  <p>In the LogCat I see this message twice:  get companies success 4</p>
  
  <p>How I can achieve that?</p>