def record(self):
        # type: () -> bytes
        '''
        A method to generate the string representing this UDF Long AD.

        Parameters:
         None.
        Returns:
         A string representing this UDF Long AD.
        '''
        if not self._initialized:
            raise pycdlibexception.PyCdlibInternalError('UDF Long AD not initialized')

        return struct.pack(self.FMT, self.extent_length, self.log_block_num,
                           self.part_ref_num, self.impl_use)
A method to generate the string representing this UDF Long AD.

        Parameters:
         None.
        Returns:
         A string representing this UDF Long AD.