code: func GetSize(fd uintptr) *remotecommand.TerminalSize {
  	winsize, err := term.GetWinsize(fd)
  	if err != nil {
  		runtime.HandleError(fmt.Errorf("unable to get terminal size: %v", err))
  		return nil
  	}
  
  	return &remotecommand.TerminalSize{Width: winsize.Width, Height: winsize.Height}
  }
docs: // GetSize returns the current size of the terminal associated with fd.