# File lib/net/ssh/service/agentforward/driver.rb, line 59
          def call_agent
            # if we have enough data to check the length of this packet
            if @data.length >= 4
              packet_length = @data[0..3].unpack('N').first
              # send the complete packet to the agent and read the
              # response
              if @data.length == (4 + packet_length)
                @agent.send_raw_packet @data
                buffer = @agent.read_raw_packet
              end
            end
            buffer
          end