private Point getAbsoluteEdgeExtremity(
     ConnectionNodeEditPart editPart, boolean isStart, Float[] preferPosition) {
   if (editPart == null) {
     return null;
   }
   PointList points = editPart.getConnectionFigure().getPoints().getCopy();
   if (points.size() == 2
       && new Point(0, 0).equals(points.getFirstPoint())
       && new Point(100, 100).equals(points.getLastPoint())) {
     // not display yet.
     if (preferPosition != null) {
       if (isStart && preferPosition[0] != null) {
         return new Point(0, preferPosition[0].intValue());
       } else if (!isStart && preferPosition[1] != null) {
         return new Point(0, preferPosition[1].intValue());
       }
     }
     return SequenceUtil.getAbsoluteEdgeExtremity(editPart, isStart, false);
   }
   return SequenceUtil.getAbsoluteEdgeExtremity(editPart, isStart, true);
 }