@Override
    public void checkInitialization(InitializableProblemHandler problemHandler)
            throws TikaConfigException {
        mustNotBeEmpty("bucket", this.bucket);
        mustNotBeEmpty("projectId", this.projectId);
    }
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