docs: @CheckForSigned
    public static long getContentLength (@Nonnull final HttpServletRequest aHttpRequest)
    {
      ValueEnforcer.notNull (aHttpRequest, "HttpRequest");
  
      if (false)
      {
        // Missing support > 2GB!!!
        return aHttpRequest.getContentLength ();
      }
  
      final String sContentLength = aHttpRequest.getHeader (CHttpHeader.CONTENT_LENGTH);
      return StringParser.parseLong (sContentLength, -1L);
    }