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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def firmware_version(self):
 """Returns a firmware identification string of the connected J-Link. It consists of the following: - Product Name (e.g. J-Link) - The string: compiled - Compile data and time. - Optional additional information. Args: self (JLink):
 the ``JLink`` instance Returns: Firmware identification string. """

        buf = (ctypes.c_char * self.MAX_BUF_SIZE)()
        self._dll.JLINKARM_GetFirmwareString(buf, self.MAX_BUF_SIZE)
        return ctypes.string_at(buf).decode()