code: function(db, namespace) {
      var collection = this;
      collection.trigger('request', collection);
      fetch(db, namespace, function(err, res) {
        if (err) {
          throw err;
        }
        collection.reset(res, {parse: true});
        collection.trigger('sync', collection);
      });
      return collection;
    }
docs: queries a MongoDB instance for index details and populates
  IndexCollection with the indexes in `namespace`.
  
  @param  {MongoClient} db     MongoDB driver db handle
  @param  {String} namespace   namespace to get indexes from, e.g. `test.foo`
  @return {IndexCollection}    collection of indexes on `namespace`