GeomPtr
 getGeometry(SegStrVct& vct)
 {
     GeomVct* lines = new GeomVct;
     for(SegStrVct::size_type i = 0, n = vct.size(); i < n; ++i) {
         SegmentString* ss = vct[i];
         lines->push_back(gf_->createLineString(*(ss->getCoordinates())));
     }
     return GeomPtr(gf_->createMultiLineString(lines));
 }