code: def test_missing_features():
      """Checks that HalfSpaceTrees works even if a feature is missing.
  
      >>> import random
      >>> from river import anomaly
      >>> from river import compose
      >>> from river import datasets
      >>> from river import metrics
      >>> from river import preprocessing
  
      >>> model = compose.Pipeline(
      ...     preprocessing.MinMaxScaler(),
      ...     anomaly.HalfSpaceTrees(seed=42)
      ... )
  
      >>> auc = metrics.ROCAUC()
  
      >>> features = list(next(iter(datasets.CreditCard()))[0].keys())
      >>> random.seed(42)
  
      >>> for x, y in datasets.CreditCard().take(8000):
      ...     del x[random.choice(features)]
      ...     score = model.score_one(x)
      ...     model.learn_one(x, y)
      ...     auc.update(y, score)
  
      >>> auc
      ROCAUC: 88.68%
  
      """
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_missing_features() without return types