code: public static String formatETag(final String etag) {
          if (etag.startsWith("\"") && etag.endsWith("\"")) {
              return etag;
          }
          else {
              return String.format("\"%s\"", etag);
          }
      }
docs: Reads character data for the Etag element from an XML stream reader.
  
  @param xmlr
  An <code>XMLStreamReader</code> object that represents the source XML stream reader.
  
  @return A <code>String</code> that represents the character data for the Etag element.