How to update tuple in groovy

Summary:

I am trying to push some data from an ASO cube to a BSO cube (having different dimensionality) with a Groovy rule.

Not able to elaborate the Tuple object.

Content (required):

I am trying to push some data from an ASO cube to a BSO cube, having different dimensionality, with a Groovy rule. I am using a DataImporter nested into a DataExporter. The data exporter provides the following chain of objects: DataImporter-> DataIterator -> RowData -> Tuple<Dimension,Member>.

I need to elaborate the Tuple in order to add a dimension which is not contained in the ASO cube so that I can use the same tuple to load the BSO cube.