title: ViewPager Inside ViewPager Not Responding
body: <p>I use <a href="https://stackoverflow.com/questions/13477820/android-vertical-viewpager">Vertical View Pager</a> in my xml</p>
  
  <pre><code>&lt;com.fadeltd.trivia.VerticalViewPager
      android:id="@+id/result_main_view_pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
  &lt;/com.fadeltd.trivia.VerticalViewPager&gt;
  </code></pre>
  
  <p>Then in my code</p>
  
  <pre><code>viewPager.setAdapter(new PagerAdapter(getSupportFragmentManager()));
  
  class PagerAdapter extends FragmentStatePagerAdapter {
      Fragment fragments[];
  
      public PagerAdapter(FragmentManager fragmentManager) {
          super(fragmentManager);
          fragments = new Fragment[]{
                  ExperienceFragment.newInstance(),
                  RankFragment.newInstance(),
                  QuestionFragment.newInstance(),
          };
      }
  
      @Override
      public Fragment getItem(int position) {
          return fragments[position];
      }
  
      @Override
      public int getCount() {
          return fragments.length;
      }
  }
  </code></pre>
  
  <p>It works fine and I can swipe up and down using the view pager, but I want to use a standard view pager with left right swipe in one of my fragment (<code>QuestionFragment</code>)</p>
  
  <pre><code>public class QuestionFragment extends Fragment {
      ...
      public void setupQuestions() {
          Fragment[] fragments = new Fragment[questionList.size()];
          for (int i = 0; i &lt; questionList.size(); i++) {
              Question question = questionList.get(i);
              switch (question.getType()) {
                  case Question.TYPE_TEXT:
                      fragments[i] = QuizTextFragment.newInstance(question);
                      break;
                  case Question.TYPE_IMAGE:
                      fragments[i] = QuizImageFragment.newInstance(question);
                      break;
                  case Question.TYPE_ESSAY:
                      fragments[i] = QuizEssayFragment.newInstance(question);
                      break;
              }
          }
  
          PagerAdapter adapter = new PagerAdapter(getChildFragmentManager(), fragments);
          QuestionViewPager.setAdapter(adapter);
      }
  
      class PagerAdapter extends FragmentStatePagerAdapter {
          Fragment[] fragments;
  
          public PagerAdapter(FragmentManager fragmentManager, Fragment[] fragments) {
              super(fragmentManager);
              this.fragments = fragments;
          }
  
          @Override
          public Fragment getItem(int position) {
              return fragments[position];
          }
  
          @Override
          public int getCount() {
              return fragments.length;
          }
      }
  }
  </code></pre>
  
  <p>But whenever I try to swipe down to the last Page from the ViewPager, My App suddenly freeze, and a few moment later, the App isn't responding</p>
  
  <p><a href="https://i.stack.imgur.com/BVg5p.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BVg5p.png" alt="Not Responding"></a></p>