code: def transform(self, sentences, contain_labels=False):
      X = [self.word2features(sentence) for sentence in sentences]
      if contain_labels:
          y = [self.sentence2labels(s) for s in sentences]
          return X, y
      return X
  
file_path: underthesea/underthesea/transformer/tagged.py
imports: import re
  from underthesea.transformer.tagged_feature import functions
label_desc: Use image node_id 4 for calling the TaggedTransformer obj's underlying member method code with example usage: obj.transform(sentences, contain_labels) and returns: X, X,  y