@Override
    public void initialize(Map<String, Param> params) throws TikaConfigException {
        //params have already been set...ignore them
        //TODO -- add other params to the builder as needed
        storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    }
This initializes the gcs storage client.

@param params params to use for initialization
@throws TikaConfigException
tika-pipes/tika-fetchers/tika-fetcher-gcs/src/main/java/org/apache/tika/pipes/fetcher/gcs/GCSFetcher.java