InsertDefaultIfAbsent

Insert the document, with its contents treated as default data, only if there is not already a document with the same identifier in the store. If there is already a document in the store with the same identifier then this will be a no-op. Use this strategy if you want to insert default data for a given document identifier, which you want to treat as common initial data amongst all peers and that you expect to be mutated or overwritten in due course.