code: private static boolean polylineOverlapsPolyline_(Polyline polyline_a,
  			Polyline polyline_b, double tolerance,
  			ProgressTracker progress_tracker) {
  		// Quick rasterize test to see whether the the geometries are disjoint.
  		if (tryRasterizedContainsOrDisjoint_(polyline_a, polyline_b, tolerance,
  				false) == Relation.disjoint)
  			return false;
  
  		return linearPathOverlapsLinearPath_(polyline_a, polyline_b, tolerance);
  	}
docs: Returns true if polyline_a overlaps polyline_b.