code: func (t *terminal) SetWinSize(params rsession.TerminalParams) error {
  	t.mu.Lock()
  	defer t.mu.Unlock()
  	if t.pty == nil {
  		return trace.NotFound("no pty")
  	}
  	if err := term.SetWinsize(t.pty.Fd(), params.Winsize()); err != nil {
  		return trace.Wrap(err)
  	}
  	t.params = params
  	return nil
  }
docs: // SetWinSize sets the window size of the terminal.