Google Cloud Storage (GCS) loader is implemented by the `google-cloud-storage-loader` module. To use it, you will need to add the following dependency to your project:

xml
<dependency>
  <groupId>${coherence.groupId}</groupId>
  <artifactId>coherence-rag-google-cloud-storage-loader</artifactId>
  <version>${coherence.version}</version>
</dependency>

This will configure document loader for the custom `gcs` URI protocol, and allow documents to be loaded from the Azure Blob Storage using the following URI syntax:

gcs://<bucket>/<object> 

For example, to load document `coherence/coherence-rag.pdf` from the `coherence-rag-docs` bucket, you would reference it as:

gcs://coherence-rag-docs/coherence/coherence-rag.pdf

For more information, please refer to [Cloud Storage documentation](https://cloud.google.com/storage/docs).