# File lib/net/ssh/authentication/agent.rb, line 83
83:     def negotiate!
84:       # determine what type of agent we're communicating with
85:       type, body = send_and_wait(SSH2_AGENT_REQUEST_VERSION, :string, Transport::ServerVersion::PROTO_VERSION)
86: 
87:       if type == SSH2_AGENT_VERSION_RESPONSE
88:         raise NotImplementedError, "SSH2 agents are not yet supported"
89:       elsif type != SSH_AGENT_RSA_IDENTITIES_ANSWER1 && type != SSH_AGENT_RSA_IDENTITIES_ANSWER2
90:         raise AgentError, "unknown response from agent: #{type}, #{body.to_s.inspect}"
91:       end
92:     end