@SuppressWarnings("unchecked")
    public final I named(String indexName) {
      options.name(indexName);
      return (I) this;
    }
Configures name for an index, that is otherwise will be auto-named by index fields.
@param indexName explicitly provided index name
@return {@code this} indexer for chained invocation
mongo/src/org/immutables/mongo/repository/Repositories.java