private static final class Resources {
    // formats
    private static final Format ps =
        PackageWriter.getFormat(
            "https://raw.github.com/nicholasdelrio/visko/master/resources/formats/POSTSCRIPT.owl#POSTSCRIPT");
    private static final Format netCDF =
        PackageWriter.getFormat(
            "https://raw.github.com/nicholasdelrio/visko/master/resources/formats/NETCDF.owl#NETCDF");
    private static final Format spaceSeparatedValues =
        PackageWriter.getFormat(
            "https://raw.github.com/nicholasdelrio/visko/master/resources/formats/SPACESEPARATEDVALUES.owl#SPACESEPARATEDVALUES");
    private static final Format esriGridded =
        PackageWriter.getFormat(
            "https://raw.github.com/nicholasdelrio/visko/master/resources/formats/ESRIGRID.owl#ESRIGRID");

    // semantic type uris
    private static final OntResource gravityData =
        PackageWriter.getDataType(
            "http://rio.cs.utep.edu/ciserver/ciprojects/CrustalModeling/CrustalModeling.owl#d19");
    private static final OntResource griddedGravityData =
        PackageWriter.getDataType(
            "http://rio.cs.utep.edu/ciserver/ciprojects/CrustalModeling/CrustalModeling.owl#d12");

    // views
    private static final VisualizationAbstraction contourMap2D =
        PackageWriter.getView(ViskoV.INDIVIDUAL_URI_2D_ContourMap);
    private static final VisualizationAbstraction rasterMap2D =
        PackageWriter.getView(ViskoV.INDIVIDUAL_URI_2D_RasterMap);
    private static final VisualizationAbstraction pointMap2D =
        PackageWriter.getView(ViskoV.INDIVIDUAL_URI_2D_PointMap);
    private static final VisualizationAbstraction barchart3D =
        PackageWriter.getView(ViskoV.INDIVIDUAL_URI_3D_BarChart);

    // data types
    private static final OntResource xyzData =
        PackageWriter.getDataType(
            "http://rio.cs.utep.edu/ciserver/ciprojects/CrustalModeling/CrustalModeling.owl#d18");
    private static final OntResource fieldTrmmedGravityData =
        PackageWriter.getDataType(
            "http://rio.cs.utep.edu/ciserver/ciprojects/CrustalModeling/CrustalModeling.owl#FieldTrimmedGravityData");
    private static final OntResource COARDS_2D_Grid =
        PackageWriter.getDataType("http://gmt.soest.hawaii.edu/gmt-data.owl#2D_Grid_COARDS");
  }