In order to learn how to use document clustering in ICA, I created a collection with document clustering enabled, then crawled and indexed a few thousand documents. I have generated a document clustering proposal, deployed that proposal with the option "Categorize to a top relevant cluster" and waited for the deployment process to complete. However, none of the documents in my collection were assigned a Document Cluster facet value. I even tried rebuilding the index afterward, and still the Document Cluster facet is not populated on any document. Is there a step I am missing?