title: FragmentPagerAdapter update title dynamically
body: <p>I have a ViewPager with FragmentPagerAdapter, which has 3 Fragments. Now, I have <strong>a number of items as part of the title</strong> of the fragment:</p>
  
  <p><img src="https://i.stack.imgur.com/hUEYi.png" alt="enter image description here"></p>
  
  <p>So user can add or remove those items, and title should update accordingly. However, this title seems static.</p>
  
  <p>How can one recall this method to update FragmentPagerAdapter's titles?</p>
  
  <pre><code>@Override
      public CharSequence getPageTitle(int position) {
          switch (position) {
              case 0: return items + " (" + notFoundItems + ")";
              case 1: return found;
              case 2: return review;
          }
          return "";
      }
  </code></pre>
  
  <p>I found a couple of similar questions on SO, but I need to update <strong>title</strong>, not only the fragment itself.</p>