_grid->GetCellPoints(vtkId, npts, pts);
// MESSAGE(vtkId << " " << npts << " " << _nbDownCells);
//ASSERT(npts == _nbDownCells);
_grid->GetCellPoints(vtkId, npts, pts);
// MESSAGE(vtkId << " " << npts << " " << _nbDownCells);
//ASSERT(npts == _nbDownCells);