/**
   * Check if Content Security Policy Level 2 is supported by the browser Currently, IE, Edge and
   * Opera Mini browsers don't support CSP2 as per http://caniuse.com/#feat=contentsecuritypolicy2
   *
   * @return true if user agent used in req supports CSP2
   */
  private boolean isCSP2Supported(final HttpServletRequest req) {
    final String userAgent = req.getHeader("User-Agent");
    if (userAgent == null) {
      return false;
    }

    final int browser = BrowserUserAgent.parseBrowser(userAgent);
    if (UserAgent.IE.match(browser)) { // UserAgent.IE is used for IE11 and IE12 (Edge)
      return false;
    }

    return true;
  }