func (b *BarChart) SetShowMarks(show bool) {
	b.mtx.Lock()
	defer b.mtx.Unlock()

	b.showMarks = show
}
func (b *BarChart) SetShowMarks(show bool) {
	b.mtx.Lock()
	defer b.mtx.Unlock()

	b.showMarks = show
}
// SetShowMarks turns on and off marks under horizontal axis