func (l *List) SetStart(i int) {
	if i < 0 {
		i = 0
	}
	if i > l.cursor {
		l.start = l.cursor
	} else {
		l.start = i
	}
}
func (l *List) SetStart(i int) {
	if i < 0 {
		i = 0
	}
	if i > l.cursor {
		l.start = l.cursor
	} else {
		l.start = i
	}
}
// SetStart sets the current scroll position. Values out of bounds will be
// clamped.