/src/main/java/org/htmlunit/util/geometry/Line2D.java
slope_ = ( endY_ - startX_) / ( endX_ - startY_) ;
slope_ = ( endY_ - startY_ ) / ( endX_ - startX_ ) ;
isVertical_ = Math.abs(startX_ - endX_) < epsilon; if (isVertical_) { slope_ = Double.NaN; yIntercept_ = Double.NaN; } else { <extra_id_0> yIntercept_ = startY_ - slope_ * startX_; } } public Point2D intersect(final Line2D line) { if (isVertical_ && line.isVertical_) { return null;