@Override
    public void renameDimensions(DimensionRenamer renamer) {
        super.renameDimensions(renamer);
        List<String> renamedDimensions = new ArrayList<>(reduceDimensions.size());
        for (String name : reduceDimensions) {
            Optional<String> newName = renamer.dimensionNameOf(name);
            if (newName.isEmpty()) {
                return;  // presumably, already renamed
            }
            renamedDimensions.add(newName.get());
        }
        reduceDimensions = renamedDimensions;
    }
ONNX Reduce[Sum/Mean/etc] operation
model-integration/src/main/java/ai/vespa/rankingexpression/importer/operations/Reduce.java