docs: def _parse_array(value):
      """Coerce value into an list.
  
      :param str value: Value to parse.
      :returns: list or None if the value is not a JSON array
      :raises: TypeError or ValueError if value appears to be an array but can't
          be parsed as JSON.
      """
      value = value.lstrip()
      if not value or value[0] not in _bracket_strings:
          return None
      return json.loads(value)