title: Why is "require UIExplorerBlock" and "require UIExplorerPage" required for some Components?
body: <p>In react-native for components such as ToolbarAndroid, Switch, ProcessBar, ToastAndroid, ListView, etc. the following is required and I have not been able to find an explanation why this is necessary:</p>
  
  <pre><code>var UIExplorerBlock = require('./UIExplorerBlock');
  var UIExplorerPage = require('./UIExplorerPage');
  </code></pre>
  
  <p>and respectively</p>
  
  <pre><code>&lt;UIExplorerPage&gt;
    &lt;UIExplorerBlock&gt;
      ..
    &lt;/UIExplorerBlock&gt;
  &lt;/UIExplorerPage&gt;
  </code></pre>