code: def compute_bucket_imbalance_score(costs, assignment):
      buckets = np.unique(assignment)
      costs_per_bucket = []
      for bucket in buckets:
          costs_per_bucket.append(np.sum(costs[assignment == bucket]))
      return np.std(costs_per_bucket)
  
imports: import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: compute_bucket_imbalance_score(costs, assignment) and returns: np