title: I try to download a google file, there isn't errors but it doesn't work
body: <p>I'm developing an app with google drive and I can see my files with these app. I want to download the files, but I can't.
  This is my function, is equal to google documentation:</p>
  
  <p>Thanks un advance!!</p>
  
  <pre><code>  /* Download a file's content.
     * 
     * @param service Drive API service instance.
     * @param file Drive File instance.
     * 
     * @return InputStream containing the file's content if successful, {@code null} otherwise.
     */
   public static InputStream downloadFile(Drive service, File file) throws IOException
   {
      if (file.getDownloadUrl() != null &amp;&amp; file.getDownloadUrl().length() &gt; 0)
       {
       try
       {
       HttpResponse resp = service.getRequestFactory().buildGetRequest(new GenericUrl(file.getDownloadUrl())).execute();
       return resp.getContent();
       }
       catch (IOException e)
       {
       // An error occurred.
       e.printStackTrace();
       return null;
       }
       }
      else
       {
       // The file doesn't have any content stored on Drive.
       return null;
       }
   }
  </code></pre>
  
  <p>No errors in Logcat, but I don't see any file in downloads, sd-card, etc </p>
  
  <p>If there isn't error, I have to see very carefull in sd-card, system etc?</p>
  
  <p>it's necessarely anything else?? </p>