# File lib/net/sftp/protocol/driver.rb, line 100
    def do_confirm( channel )
      assert_state :unconfirmed
      @log.debug "requesting sftp subsystem" if @log.debug?

      channel.subsystem  "sftp"
      channel.on_success &method( :do_success )
      channel.on_data    &method( :do_data )

      @state = :init
    end