docs: function ModelIndices(model) {
      // For now the only indices we construct are for flowEvents
      this.flowEventsById_ = {};
      model.flowEvents.forEach(function(fe) {
        if (fe.id !== undefined) {
          if (!this.flowEventsById_.hasOwnProperty(fe.id)) {
            this.flowEventsById_[fe.id] = new Array();
          }
          this.flowEventsById_[fe.id].push(fe);
        }
      }, this);
    }