grib/src/main/java/ucar/nc2/grib/grib1/tables/Grib1ParamTables.java
static int makeKey(int center, int subcenter, int version) {
    if (center < 0) center = 255;
    if (subcenter < 0) subcenter = 255;
    if (version < 0) version = 255;
    return center * 1000 * 1000 + subcenter * 1000 + version;
  }
static int makeKey(int center, int subcenter, int version) {
    if (center < 0) center = 255;
    if (subcenter < 0) subcenter = 255;
    if (version < 0) version = 255;
    return center * 1000 * 1000 + subcenter * 1000 + version;
  }
Make a key from (center, subcenter, version) that provides correct sort order.