How to use the defusedxml.cElementTree.fromstring function in defusedxml

def get_snapshot_info(self, **kwargs):
        """Execute get_snapshot_info API."""
        res_details = self._get_res_details(
            '/cgi-bin/disk/snapshot.cgi?',
            func='extra_get',
            LUNIndex=kwargs['lun_index'],
            snapshot_list='1',
            snap_start='0',
            snap_count='100',
            sid=self.sid)

        root = ET.fromstring(res_details['data'])
        if root.find('authPassed').text == '0':
            raise exception.VolumeBackendAPIException(
                data=_('Session id expired'))
        if root.find('result').text < '0':
            raise exception.VolumeBackendAPIException(
                data=_('Unexpected response from QNAP API'))

        snapshot_list = root.find('SnapshotList')
        if snapshot_list is None:
            return None
        snapshot_tree = snapshot_list.findall('row')
        for snapshot in snapshot_tree:
            if (kwargs['snapshot_name'] ==
                    snapshot.find('snapshot_name').text):
                return snapshot

def execute_login(self):
        """Login and return sid."""
        params = OrderedDict(
            pwd=base64.b64encode(self.password.encode('utf-8')).decode(),
            serviceKey='1',
            user=self.username,
        )
        encoded_params = urllib.parse.urlencode(params)
        url = ('/cgi-bin/authLogin.cgi?')

        res_details = self._execute_and_get_response_details(
            self.ip, url, encoded_params)
        root = ET.fromstring(res_details['data'])
        LOG.debug('execute_login data: %s', res_details['data'])
        session_id = root.find('authSid').text
        LOG.debug('execute_login session_id: %s', session_id)
        return session_id

def delete_snapshot_api(self, snapshot_id):
        """Execute CGI to delete snapshot by snapshot id."""
        res_details = self._get_res_details(
            '/cgi-bin/disk/snapshot.cgi?',
            func='del_snapshots',
            snapshotID=snapshot_id,
            sid=self.sid)

        root = ET.fromstring(res_details['data'])
        if root.find('authPassed').text == '0':
            raise exception.VolumeBackendAPIException(
                data=_('Session id expired'))
        # snapshot not exist
        if root.find('result').text == '-206021':
            return
        # lun not exist
        if root.find('result').text == '-200005':
            return
        if root.find('result').text < '0':
            raise exception.VolumeBackendAPIException(
                data=_('delete snapshot %s failed') % snapshot_id)

def get_one_lun_info(self, lunID):
        """Execute get_one_lun_info API."""
        res_details = self._get_res_details(
            '/cgi-bin/disk/iscsi_portal_setting.cgi?',
            func='extra_get',
            lun_info='1',
            lunID=lunID,
            sid=self.sid)

        root = ET.fromstring(res_details['data'])
        if root.find('authPassed').text == '0':
            raise exception.VolumeBackendAPIException(
                data=_('Session id expired'))
        else:
            return res_details

def convert_queue_status(queue_status_output):
        def leaf_to_dict(leaf):
            return [{sub_child.tag: sub_child.text for sub_child in child} for child in leaf]

        tree = ETree.fromstring(queue_status_output)
        df_running_jobs = pandas.DataFrame(leaf_to_dict(leaf=tree[0]))
        df_pending_jobs = pandas.DataFrame(leaf_to_dict(leaf=tree[1]))
        df_merge = df_running_jobs.append(df_pending_jobs, sort=True)
        df_merge.state[df_merge.state == 'r'] = 'running'
        df_merge.state[df_merge.state == 'qw'] = 'pending'
        df_merge.state[df_merge.state == 'Eqw'] = 'error'
        return pandas.DataFrame({'jobid': pandas.to_numeric(df_merge.JB_job_number),
                                 'user': df_merge.JB_owner,
                                 'jobname': df_merge.JB_name,
                                 'status': df_merge.state})

def _get_portal_info(self, volume, connector, lun_slot_id, lun_owner):
        """Get portal info."""
        # Cache portal info for twenty seconds
        # If connectors were the same then use the portal info which was cached
        LOG.debug('get into _get_portal_info')
        self.initiator = connector['initiator']
        ret = self.api_executor.get_iscsi_portal_info()
        root = ET.fromstring(ret['data'])
        iscsi_port = root.find('iSCSIPortal').find('servicePort').text
        LOG.debug('iscsiPort: %s', iscsi_port)
        target_iqn_prefix = root.find(
            'iSCSIPortal').find('targetIQNPrefix').text
        LOG.debug('targetIQNPrefix: %s', target_iqn_prefix)

        internal_model_name = (self.nasInfoCache
                               [self.configuration.qnap_management_url][1])
        LOG.debug('internal_model_name: %s', internal_model_name)
        fw_version = (self.nasInfoCache
                      [self.configuration.qnap_management_url][2])
        LOG.debug('fw_version: %s', fw_version)

        target_index = ''
        target_iqn = ''

def get_target_info(self, target_index):
        """Get nas target info."""
        res_details = self._get_res_details(
            '/cgi-bin/disk/iscsi_portal_setting.cgi?',
            func='extra_get',
            targetInfo=1,
            targetIndex=target_index,
            ha_sync='1',
            sid=self.sid)

        root = ET.fromstring(res_details['data'])
        LOG.debug('TS get_target_info.authPassed: (%s)',
                  root.find('authPassed').text)
        if root.find('authPassed').text == '0':
            raise exception.VolumeBackendAPIException(
                data=_('Session id expired'))
        if root.find('result').text < '0':
            raise exception.VolumeBackendAPIException(
                data=_('Get target info failed'))

        target_list = root.find('targetInfo')
        target_tree = target_list.findall('row')
        for target in target_tree:
            if target_index == target.find('targetIndex').text:
                return target

res_details = self._get_res_details(
            '/cgi-bin/disk/iscsi_target_setting.cgi?',
            func='add_init',
            targetIQN=target_iqn,
            initiatorIQN=init_iqn,
            initiatorAlias=init_iqn,
            bCHAPEnable='1' if use_chap_auth else '0',
            CHAPUserName=chap_username,
            CHAPPasswd=chap_password,
            bMutualCHAPEnable='0',
            mutualCHAPUserName='',
            mutualCHAPPasswd='',
            ha_sync='1',
            sid=self.sid)

        root = ET.fromstring(res_details['data'])
        if root.find('authPassed').text == '0':
            raise exception.VolumeBackendAPIException(
                data=_('Session id expired'))
        if root.find('result').text < '0':
            raise exception.VolumeBackendAPIException(
                data=_('Add target acl failed'))