Document Store Plugin

public class TestDocumentStorePlugin implements SBQQ.DocumentStorePlugin {

   public void storeDocument(SObject quote, SObject document, Blob content) {
       // Custom document saving logic goes here.
   }

   // Reserved for future use
   public Boolean isQuoteDocumentSaved() {
      return true;
   }

   // Reserved for future use
   public SObject[] listDocuments(SObject quote) {
      return null;
   }

}