# File lib/openid/consumer.rb, line 377
    def construct_redirect(auth_req, return_to, trust_root)
      redir_args = {
        "openid.identity" => auth_req.server_id,
        "openid.return_to" => return_to,
        "openid.trust_root" => trust_root,
        "openid.mode" => @mode
      }

      assoc = self.get_association(auth_req.server_url)
      redir_args["openid.assoc_handle"] = assoc.handle unless assoc.nil?

      OpenID::Util.append_args(auth_req.server_url, redir_args).to_s
    end