public com.google.api.ads.admanager.axis.v201902.HistoricalAdjustment getHistoricalAdjustment() {
        return historicalAdjustment;
    }
public com . google . api . ads . admanager . axis . v201902 . HistoricalAdjustment getHistoricalAdjustment ( ) { return historicalAdjustment ; }
Gets the historicalAdjustment value for this TrafficForecastAdjustmentSegment.

@return historicalAdjustment   * The content of the adjustment which references historical data.
This field should be set if
{@code basisType} is {@link BasisType.HISTORICAL}
and null if {@link BasisType.ABSOLUTE}.