title: Clicking on item programmatically in RecyclerView
body: <p>I am loading a list of categories and depending on which is selected, I need to show the products of the corresponding category in the <code>RecyclerView</code>.
  So when I first start the <code>Fragment</code> I need to simulate the user clicking in a default category - in this case, it would be the first one.</p>
  
  <p>How can I perform this?</p>