ProjectionOp
From www.b-kaempgen.de
This operator defines the projected measures. Note: ProjectionOp explicitly defines the selected measures, it does not remove selected measures from the cube but instead removes the non-selected measures. We assume a LEAN Data Cube (i.e., dataset with observations on the lowest levels only).
ProjectionOp gets as input an input operator and a List<Node[]> list with a header and measures according to Olap4ld_Metadata#getMeasures.28.29.
