class WEBrick::HTTPResponse

def set_error(ex, backtrace=false)
  case ex
  when HTTPStatus::Status
    @keep_alive = false if HTTPStatus::error?(ex.code)
    self.status = ex.code
  else
    @keep_alive = false
    self.status = HTTPStatus::RC_INTERNAL_SERVER_ERROR
  end
  @header['content-type'] = "text/html; charset=ISO-8859-1"
  if respond_to?(:create_error_page)
    create_error_page()
    return
  end
  if @request_uri
    host, port = @request_uri.host, @request_uri.port
  else
    host, port = @config[:ServerName], @config[:Port]
  end
  error_body(backtrace, ex, host, port)
end