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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:
 async def losetup(self, image, read_only=True, offset=None, size=None, no_part_scan=None):
 """ Setup a loop device. :param str image: path of the image file :param bool read_only: :param int offset: :param int size: :param bool no_part_scan: :returns: the device object for the loop device """

        try:
            device = self.udisks.find(image)
        except FileNotFoundError:
            pass
        else:
            self._log.info(_('not setting up {0}: already up', device))
            return device
        if not os.path.isfile(image):
            self._log.error(_('not setting up {0}: not a file', image))
            return None
        self._log.debug(_('setting up {0}', image))
        fd = os.open(image, os.O_RDONLY)
        device = await self.udisks.loop_setup(fd, {
            'offset': offset,
            'size': size,
            'read-only': read_only,
            'no-part-scan': no_part_scan,
        })
        self._log.info(_('set up {0} as {1}', image,
                         device.device_presentation))
        return device