code: def to_text_classification_format(self) -> str:
      labels_text = " ".join(
          [f"__label__{label.value}" for label in self.labels]
      )
      output = f"{labels_text} {self.text}"
      return output
  
file_path: underthesea/underthesea/corpus/data.py
imports: from typing import List, Union
label_desc: Use image node_id 4 for calling the Sentence obj's underlying member method code with example usage: obj.to_text_classification_format() and returns: output