rangeValue method
Implementation
@override
num rangeValue(DynamicData domainData) {
int diff = _convert(domain.first, domainData.data, splitType);
int diff2 = (_lineScale.domain.last - _lineScale.domain.first).toInt();
double p = diff / diff2;
return this.range.first + (this.range.last - this.range.first) * p;
}