constructor(tracker, edgeTypeSubscriberRegistry) {

    this.getTiddlerById = tracker.getTiddlerById.bind(tracker);
    this.getId = tracker.getIdByTiddler.bind(tracker);
    this.assignId = tracker.assignId.bind(tracker);

    this.edgeTypeSubscriberRegistry = edgeTypeSubscriberRegistry;

    this.indeces = $tm.indeces;
    this.wiki = $tw.wiki;

    this.visShapesWithTextInside = utils.getLookupTable([
      'ellipse', 'circle', 'database', 'box', 'text'
    ]);

  }
@param {Tracker} tracker
@param {EdgeTypeSubscriberRegistry} edgeTypeSubscriberRegistry