func (b *BarChart) SetData(data []BarData) {
	b.mtx.Lock()
	defer b.mtx.Unlock()

	b.data = make([]BarData, len(data))
	copy(b.data, data)
}
func (b *BarChart) SetData(data []BarData) {
	b.mtx.Lock()
	defer b.mtx.Unlock()

	b.data = make([]BarData, len(data))
	copy(b.data, data)
}
func ( b * BarChart ) SetData ( data [ ] BarData ) { b . mtx . Lock ( ) defer b . mtx . Unlock ( ) b . data = make ( [ ] BarData , len ( data ) ) copy ( b . data , data ) }
// SetData assign a new bar list to a chart
SetData assign a new bar list to a chart