code: def extract_lookups(value):
      
      lookups = set()
      if isinstance(value, basestring):
          lookups = lookups.union(extract_lookups_from_string(value))
      elif isinstance(value, list):
          for v in value:
              lookups = lookups.union(extract_lookups(v))
      elif isinstance(value, dict):
          for v in value.values():
              lookups = lookups.union(extract_lookups(v))
      return lookups
docs: Recursively extracts any stack lookups within the data structure.
  
      Args:
          value (one of str, list, dict): a structure that contains lookups to
              output values
  
      Returns:
          list: list of lookups if any