code: def min_distance(self, dist, min_dist_set):
      """
      Find the vertex that is closest to the visited set
      """
      min_dist = float("inf")
      for target in range(self.vertex_count):
          if min_dist_set[target]:
              continue
          if dist[target] < min_dist:
              min_dist = dist[target]
              min_index = target
      return min_index
  
label_desc: Use image node_id 2 for calling the Dijkstra obj's underlying member method code with example usage: obj.min_distance(dist, min_dist_set) and returns: min_index