connect! (Net::SSH::UserAuth::Agent)

    # File lib/net/ssh/userauth/agent.rb, line 69
            def connect!
              @socket = @socket_factory.open( @socket_name )

              # determine what type of agent we're communicating with
              buffer = @buffers.writer
              buffer.write_string Net::SSH::Transport::Session.version
              type, body = send_with_reply SSH2_AGENT_REQUEST_VERSION, buffer

              if type == SSH2_AGENT_VERSION_RESPONSE
                raise NotImplementedError, "SSH2 agents are not yet supported"
              elsif type != SSH_AGENT_RSA_IDENTITIES_ANSWER
                raise AgentError,
                  "unknown response from agent: #{type}, #{body.to_s.inspect}"
              end
            end