public EnumerableSolids Xor(KtSolidRegion _)
        {
            //var (solid, hollow) = Clip(region, ClipType.ctXor);
            //var hol = holes.Clip(region, ClipType.ctUnion, true);
#pragma warning disable RCS1079 // Throwing of new NotImplementedException.
            throw new NotImplementedException("XOR method has not been fully implemented yet");
#pragma warning restore RCS1079 // Throwing of new NotImplementedException.
        }
 public EnumerableSolids Add(KtSolidRegion solid)
 {
     var(mainSolids, mainHollows)   = Clip(solid, ClipType.ctUnion);
     var(additionalSolids, hollows) = FixHoles(solid);
     foreach (var reg in mainSolids.Concat(additionalSolids))
     {
         reg.holes = hollows.Concat(mainHollows).Where(reg.Inscribes).ToList();
         yield return(reg);
     }
 }