addInitialFeatures_(frameState) {
    const source = this.getLayer().getSource();
    const userProjection = getUserProjection();
    let projectionTransform;
    if (userProjection) {
      projectionTransform = getTransformFromProjections(
        userProjection,
        frameState.viewState.projection,
      );
    }
    this.batch_.addFeatures(source.getFeatures(), projectionTransform);
    this.sourceListenKeys_ = [
      listen(
        source,
        VectorEventType.ADDFEATURE,
        this.handleSourceFeatureAdded_.bind(this, projectionTransform),
      ),
      listen(
        source,
        VectorEventType.CHANGEFEATURE,
        this.handleSourceFeatureChanged_.bind(this, projectionTransform),
        this,
      ),
      listen(
        source,
        VectorEventType.REMOVEFEATURE,
        this.handleSourceFeatureDelete_,
        this,
      ),
      listen(
        source,
        VectorEventType.CLEAR,
        this.handleSourceFeatureClear_,
        this,
      ),
    ];
  }
@private
@param {import("../../Map.js").FrameState} frameState Frame state.