code: def check_roc_auc(anomaly_detector, dataset):
      """The ROC AUC should always be above 50%."""
  
      from sklearn import metrics
  
      scores = []
      labels = []
  
      for x, y in dataset:
          anomaly_detector.learn_one(x)
          y_pred = anomaly_detector.score_one(x)
  
          scores.append(y_pred)
          labels.append(y)
  
      assert metrics.roc_auc_score(labels, scores) >= 0.5
  
label_desc: Use image node_id 1 for calling a global function with example usage: check_roc_auc(anomaly_detector, dataset) without return types