getTiddlersByIds(nodeIds) {

    // transform into a hashmap with all values being true
    if (Array.isArray(nodeIds)) {
      nodeIds = utils.getArrayValuesAsHashmapKeys(nodeIds);
    } else if (nodeIds instanceof vis.DataSet) {
      nodeIds = utils.getLookupTable(nodeIds, 'id'); // use id field as key
    }

    const result = [];
    for (let id in nodeIds) {
      const tRef = this.getTiddlerById(id);
      if (tRef) {
        result.push(tRef);
      }
    }

    return result;

  }
Retrieve tiddlers based on the a list of corresponding ids.

@param {Array.<Id>|Hashmap.<Id, *>|vis.DataSet} nodeIds - The ids.
@return {Array<TiddlerReference>} The resulting tiddlers.