getLifecycleListing(bucketName, listingParams, log, cb) {
        assert.strictEqual(typeof bucketName, 'string');
        log.trace('performing metadata get object listing for lifecycle',
            { listingParams });
        metadata.listLifecycleObject(bucketName, listingParams, log,
            (err, listResponse) => {
                if (err) {
                    log.debug('error from metadata', { error: err });
                    return cb(err);
                }
                return cb(null, listResponse);
            });
    }
Gets list of objects ready to be lifecycled
@param {object} bucketName - bucket in which objectMetadata is stored
@param {object} listingParams - params object passing on
needed items from request object
@param {object} log - request logger instance
@param {function} cb - callback to bucketGet.js
@return {undefined}
JSON response from metastore