code: def _as_feature(self) -> List[float]:
      return [1.0 if self.value is not None else 0.0]
  
imports: import logging
  from abc import ABC, abstractmethod
  from typing import Any, Dict, List, Optional, Text, Type
  import rasa.shared.core.constants
  from rasa.shared.exceptions import RasaException
  import rasa.shared.utils.common
  import rasa.shared.utils.io
  from rasa.shared.constants import DOCS_URL_SLOTS
label_desc: Use image node_id 1 for calling the TextSlot obj's underlying member method code with example usage: obj._as_feature() and returns: list