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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 _get_disk_size(self, device):
        '''
        Get a size of a disk.
        '''
        out = __salt__['cmd.run_all']("df {0}".format(device))
        if out['retcode']:
            msg = "Disk size info error: {0}".format(out['stderr'])
            log.error(msg)
            raise SIException(msg)

        devpath, blocks, used, available, used_p, mountpoint = [elm for elm in
                                                                out['stdout'].split(os.linesep)[-1].split(" ") if elm]
        return {
            'device': devpath, 'blocks': blocks, 'used': used,
            'available': available, 'used (%)': used_p, 'mounted': mountpoint,
        }