+ /**
+ * Tries to read from the given URL. If successful, saves a reader to the
+ * response in field {@code dataIn}, otherwise (on exception, or HTTP response
+ * status not 200), throws an exception.
+ * <p>
+ * If the response status includes
+ *
+ * <pre>
+ * Content-Type : application/x-gzip
+ * </pre>
+ *
+ * then tries to read as gzipped content.
+ *
+ * @param urlStr
+ * @throws IOException
+ * @throws MalformedURLException
+ */
+ private void checkURLSource(String urlStr)
+ throws IOException, MalformedURLException