def load_selection():
        """
        Loads a platform/device selection from disk and returns a tuple
        ``(platform, device)``. Each entry in the tuple is either a string
        with the platform/device name, or ``None`` if no preference was set.
        """
        platform, device = OpenCL.load_selection_bytes()
        if platform:
            platform = platform.decode('ascii')
        if device:
            device = platform.decode('device')

        return platform, device
    def get_platform(self):
        '''
        return the platform name
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~Platform\x00'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string,
                                           response_size)
        if cmd_response.get('status'):
            platform = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            platform = platform.replace(b'=', b'')
            return platform.decode()
        else:
            raise ZKErrorResponse("Can't get platform")