code: def _ensure_list(value):
      if value is None:
          return []
  
      if isinstance(value, list):
          return value
  
      return [value]
  
imports: import logging
  import os
  import jinja2
  import eta.core.utils
  import fiftyone.constants
  import fiftyone.core.labels
  import fiftyone.core.metadata
  import fiftyone.core.storage
  import fiftyone.core.utils
  import fiftyone.utils.data
label_desc: Use image node_id 2 for calling a global function with example usage: _ensure_list(value) and returns: list, list, value