code: def mutual_weight(G, u, v, weight=None):
      """Returns the sum of the weights of the edge from `u` to `v` and
      the edge from `v` to `u` in `G`.
  
      `weight` is the edge data key that represents the edge weight. If
      the specified key is `None` or is not in the edge data for an edge,
      that edge is assumed to have weight 1.
  
      Pre-conditions: `u` and `v` must both be in `G`.
  
      """
      try:
          a_uv = G[u][v].get(weight, 1)
      except KeyError:
          a_uv = 0
      try:
          a_vu = G[v][u].get(weight, 1)
      except KeyError:
          a_vu = 0
      return a_uv + a_vu
  
imports: import networkx
label_desc: Use image node_id 1 for calling a global function with example usage: mutual_weight(G, u, v, weight) and returns: unknown