+ contructs the visited nodes for CH
	+store the visitednodes array of the source
	+ store the visitednodes array of the target
	+ make a method get visited nodes (concatenate visitednodes source and
target)
+ extract path from CH
	+ store the minimum node point
	+ store the previous array of the source
	+ store the previous array of the target
	+ replace shortcuts by "real" edges when constructing paths
	+ merge two paths
+ in experiment class also write stats about the graph the experiment is
conducted on
+ write unit test for extracting paths
	+ test when no shortcuts in path
	+ test when shortcuts in path