code: private static boolean polylineRelatePolyline_(Polyline polyline_a,
  			Polyline polyline_b, double tolerance, int relation,
  			ProgressTracker progress_tracker) {
  		switch (relation) {
  		case Relation.disjoint:
  			return polylineDisjointPolyline_(polyline_a, polyline_b, tolerance,
  					progress_tracker);
  
  		case Relation.within:
  			return polylineContainsPolyline_(polyline_b, polyline_a, tolerance,
  					progress_tracker);
  
  		case Relation.contains:
  			return polylineContainsPolyline_(polyline_a, polyline_b, tolerance,
  					progress_tracker);
  
  		case Relation.equals:
  			return polylineEqualsPolyline_(polyline_a, polyline_b, tolerance,
  					progress_tracker);
  
  		case Relation.touches:
  			return polylineTouchesPolyline_(polyline_a, polyline_b, tolerance,
  					progress_tracker);
  
  		case Relation.overlaps:
  			return polylineOverlapsPolyline_(polyline_a, polyline_b, tolerance,
  					progress_tracker);
  
  		case Relation.crosses:
  			return polylineCrossesPolyline_(polyline_a, polyline_b, tolerance,
  					progress_tracker);
  
  		default:
  			break; // warning fix
  		}
  
  		return false;
  	}
docs: Returns true if the relation holds.