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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 unlock(self):
 """Unlocks the device connected to the J-Link. Unlocking a device allows for access to read/writing memory, as well as flash programming. Note: Unlock is not supported on all devices. Supported Devices: Kinetis Returns: ``True``. Raises: JLinkException: if the device fails to unlock. """

        if not unlockers.unlock(self, self._device.manufacturer):
            raise errors.JLinkException('Failed to unlock device.')

        return True