code: private static int[] lift(int[] path, int[] mapping) {
          for (int i = 0; i < path.length; i++) {
              path[i] = mapping[path[i]];
          }
          return path;
      }
docs: Internal - lifts a path in a subgraph back to the original graph.
  
  @param path    a path
  @param mapping vertex mapping
  @return the lifted path