title: LiveData, Transformations.map() - How to force to refresh when the user changes filtering order?
body: <p>I use <code>LiveData</code> + <code>Transformations.map()</code> :</p>
  
  <pre><code>private final LiveData&lt;List&lt;Task&gt;&gt; observableTasks;
  (...)
  observableTasks =  Transformations.map(tasksRepository.getTasks(), tasks-&gt; filterTasks(tasks));
  </code></pre>
  
  <p>How to force <code>LiveData</code> to refresh? I need <code>Transformations.map()</code> to prepare new list. When the user changes filtering options I need to call <code>filterTasks(tasks)</code> again and show new, sorted list. Data coming from the repository (<code>tasksRepository.getTasks()</code>) stays the same.</p>