# File lib/net/ssh/service/forward.rb, line 176
    def agent(channel)
      return if @agent_forwarded
      @agent_forwarded = true

      channel.send_channel_request("auth-agent-req@openssh.com") do |achannel, success|
        if success
          debug { "authentication agent forwarding is active" }
        else
          achannel.send_channel_request("auth-agent-req") do |a2channel, success2|
            if success2
              debug { "authentication agent forwarding is active" }
            else
              error { "could not establish forwarding of authentication agent" }
            end
          end
        end
      end
    end