code: def from_json(cls, raw):
          
          bcls = None
          if 'webLink' in raw:
              bcls = WebLink
          elif 'topicCategory' in raw:
              bcls = Category
          elif 'taskAssist' in raw:
              bcls = TaskAssist
          elif 'context' in raw:
              bcls = Context
  
          if bcls is None:
              logger.warning('Unknown annotation type: %s', raw.keys())
              return None
          annotation = bcls()
          annotation.load(raw)
  
          return annotation
docs: Helper to construct an annotation from a dict.
  
          Args:
              raw (dict): Raw annotation representation.
  
          Returns:
              Node: An Annotation object or None.