code: public Bucket updateBucket(String bucketName) {
      // [START updateBucket]
      BucketInfo bucketInfo = BucketInfo.newBuilder(bucketName).setVersioningEnabled(true).build();
      Bucket bucket = storage.update(bucketInfo);
      // [END updateBucket]
      return bucket;
    }
docs: [VARIABLE "my_unique_bucket"]