Stratum and Layer

public List<LayerInfo> getLayerStack(E_product board) throws SdaiException {
    List<LayerInfo> layers = new ArrayList<>();
    List<E_stratum> stratums = getStratums(board);

    // Sort by position
    stratums.sort(Comparator.comparingInt(this::getStratumPosition));

    for (E_stratum stratum : stratums) {
        LayerInfo info = new LayerInfo();
        info.name = stratum.getName(null);
        info.technology = getStratumTechnology(stratum);
        info.thickness = getStratumThickness(stratum);
        info.material = getStratumMaterial(stratum);
        layers.add(info);
    }
    return layers;
}

public class LayerInfo {
    String name;       // e.g., "Top Copper", "Prepreg 1"
    String technology; // e.g., "signal", "ground", "power", "dielectric"
    double thickness;  // in mm
    String material;   // e.g., "Copper", "FR-4"
}

public List<ViaInfo> getVias(E_product board) throws SdaiException {
    List<ViaInfo> vias = new ArrayList<>();
    List<E_inter_stratum_feature> features = getInterStratumFeatures(board);

    for (E_inter_stratum_feature via : features) {
        ViaInfo info = new ViaInfo();
        info.name = via.getName(null);
        info.startLayer = getStartLayer(via);
        info.endLayer = getEndLayer(via);
        info.location = getViaLocation(via);
        info.padSize = getViaPadSize(via);
        vias.add(info);
    }
    return vias;
}

public List<E_shape_aspect> getFeaturesOnLayer(E_product board, String layerName)
        throws SdaiException {
    E_stratum stratum = findStratum(board, layerName);
    return getShapeAspectsForStratum(stratum);
}