renderDeclutter(frameState, layerState) {
    const declutterGroup = this.getDeclutter();
    if (declutterGroup in frameState.declutter === false) {
      frameState.declutter[declutterGroup] = new RBush(9);
    }
    this.getRenderer().renderDeclutter(frameState, layerState);
  }
Render declutter items for this layer
@param {import("../Map.js").FrameState} frameState Frame state.
@param {import("../layer/Layer.js").State} layerState Layer state.
@override