Read Source Data for Summary Function

Hello,

I'm working on a rule that drills back into source stage data from the target summary table. I'm receiving an error on the ReadSourceDataForSummaryRow line that the method or operation is not implemented. I've verified that the parameters I'm passing are correct and in the correct format.

Dim importTable As List(Of TargetDataInfo) = BRApi.Import.Data.ReadSummaryTargetData(si, si.WorkflowClusterPk, Nothing)

If importTable.Count > 0
	For Each importLine As TargetDataInfo In importTable
		Dim summaryRowID As Guid = importLine.SummaryRowID
		
		api.LogMessage("before, summaryRowID: " & summaryRowID.ToString)
		Dim sourceLinesForSummaryID As List(Of SourceDataInfo) = BRApi.Import.Data.ReadSourceDataForSummaryRow(si, summaryRowId)
		api.LogMessage("after")
		
	Next
End If

Has anyone else encountered this issue before? I'm working in OS version 8.2.3, but didn't see anything relevant in subsequent release notes.

Thank you!