API TLE generation
Once we have initialize TLE(s) data (see here) and options (see here), we will have to instantiate a GtmBuilder as is:
// TLE builder
final GtmBuilder build = new GtmBuilder(TLE_OBJ, geo.getSpacecraftStateList(), null);
// Building TLE final List<TLE> bestTles = build.computeBestTles(data, false);