code: def aggregated_contribution(contribution_map):
      contr_sum = {}
      for j, dct in enumerate(contribution_map):
          for k in set(dct.keys()).union(set(contr_sum.keys())):
              contr_sum[k] = (
                  contr_sum.get(k, 0) * j + dct.get(k, 0)
              ) / (j + 1)
      return contr_sum
  
label_desc: Use image node_id 1 for calling a global function with example usage: aggregated_contribution(contribution_map) and returns: contr_sum