code: func (l *List) Prev() {
  	if l.cursor > 0 {
  		l.cursor--
  	}
  
  	if l.start > l.cursor {
  		l.start = l.cursor
  	}
  }
docs: // Prev moves the visible list back one item. If the selected item is out of
  // view, the new select item becomes the last visible item. If the list is
  // already at the top, nothing happens.