code: def rarity_log(brands, exemplars):
      
      rarity = compute_rarity_scores_log(exemplars)
      scores = {}
      for brand, followers in brands:
          scores[brand] = sum(rarity[f] for f in followers) / len(followers)
      return scores
docs: Compute a score for each follower that is sum_i (1/log(n_i)), where n_i is the degree of the ith exemplar they follow.
      The score for a brand is then the average of their follower scores.