_updateDataset(index, mode) {
    const meta = this.getDatasetMeta(index);
    const args = {meta, index, mode, cancelable: true};

    if (this.notifyPlugins('beforeDatasetUpdate', args) === false) {
      return;
    }

    meta.controller._update(mode);

    args.cancelable = false;
    this.notifyPlugins('afterDatasetUpdate', args);
  }
Updates dataset at index unless a plugin returns `false` to the `beforeDatasetUpdate`
hook, in which case, plugins will not be called on `afterDatasetUpdate`.
@private