in src/dataViewBuilder/dataViewBuilder.ts [365:375]
private isLegalDataView(dataView: DataView): boolean {
if (this.hasDynamicSeries()
&& this.hasStaticSeries()
&& CategoricalDataViewBuilder.isVisualDataView(dataView.metadata.columns)) {
// It is illegal to have both dynamic series and static series in a visual DataViewCategorical,
// because the DataViewValueColumns interface today cannot express that 100% (see its 'source' property and return value of its 'grouped()' function).
return false;
}
return true;
}