private void collectLineEdge(DirectedEdge de,int opCode,List edges){
  Label label=de.getLabel();
  Edge e=de.getEdge();
  if (de.isLineEdge()) {
    if (!de.isVisited() && OverlayOp.isResultOfOp(label,opCode) && !e.isCovered()) {
      edges.add(e);
      de.setVisitedEdge(true);
    }
  }
}

private void collectLineEdge ( DirectedEdge de , int opCode , List edges ) { Label label = de . getLabel ( ) ; Edge e = de . getEdge ( ) ; if ( de . isLineEdge ( ) ) { if ( ! de . isVisited ( ) && OverlayOp . isResultOfOp ( label , opCode ) && ! e . isCovered ( ) ) { edges . add ( e ) ; de . setVisitedEdge ( true ) ; } } }
collect line edges which are in the result . line edges are in the result if they are not part of an area boundary , if they are in the result of the overlay operation , and if they are not covered by a result area .
