code: def _ParseCString(self, page_data, string_offset):
      
      cstring_map = self._GetDataTypeMap('cstring')
  
      try:
        value_string = self._ReadStructureFromByteStream(
            page_data[string_offset:], string_offset, cstring_map)
      except (ValueError, errors.ParseError) as exception:
        raise errors.ParseError((
            'Unable to map string data at offset: 0x{0:08x} with error: '
            '{1!s}').format(string_offset, exception))
  
      return value_string.rstrip('\x00')
docs: Parses a C string from the page data.
  
      Args:
        page_data (bytes): page data.
        string_offset (int): offset of the string relative to the start
            of the page.
  
      Returns:
        str: string.
  
      Raises:
        ParseError: when the string cannot be parsed.