func (b *BarChart) AddData(val BarData) {
	b.mtx.Lock()
	defer b.mtx.Unlock()

	b.data = append(b.data, val)
}
func (b *BarChart) AddData(val BarData) {
	b.mtx.Lock()
	defer b.mtx.Unlock()

	b.data = append(b.data, val)
}
func ( b * BarChart ) AddData ( val BarData ) { b . mtx . Lock ( ) defer b . mtx . Unlock ( ) b . data = append ( b . data , val ) }
// AddData appends a new bar to a chart
AddData appends a new bar to a chart