_getRingWeightOffset(datasetIndex) {
    let ringWeightOffset = 0;

    for (let i = 0; i < datasetIndex; ++i) {
      if (this.chart.isDatasetVisible(i)) {
        ringWeightOffset += this._getRingWeight(i);
      }
    }

    return ringWeightOffset;
  }
Get radius length offset of the dataset in relation to the visible datasets weights. This allows determining the inner and outer radius correctly
@private