def rescue_status_code_exception(&blk)
      yield
    rescue HtmlUnit::FailingHttpStatusCodeException => e
      raise NavigationException, e.message, caller
    end
def rescue_status_code_exception(&blk)
      yield
    rescue HtmlUnit::FailingHttpStatusCodeException => e
      raise NavigationException, e.message, caller
    end
Rescues HtmlUnit::FailingHttpStatusCodeException and re-raises as
 Celerity::NavigationException to avoid the huge JRuby backtrace