selectNodesByReferences(tiddlers, { addProperties, outputType } = {}) {

    const result = utils.makeHashMap();
    const keys = Object.keys(tiddlers);

    for (let i = keys.length; i--;) {

      const node = this.makeNode(tiddlers[keys[i]], addProperties);
      if (node) {
        result[node.id] = node;
      }

    }

    return utils.convert(result, outputType);

  }
Returns a set of nodes that corresponds to a set of tiddlers.

@param {TiddlerCollection} tiddlers - A collection of tiddlers.
@param {Hashmap} [addProperties] - a hashmap
@param {CollectionTypeString} [outputType='dataset'] - The result type.

@return {NodeCollection} A collection of a type specified in the options.