renderSources(frameState, sources) {
    const layerRenderer = this.getRenderer();
    let canvas;
    for (let i = 0, ii = sources.length; i < ii; ++i) {
      this.renderedSource_ = sources[i];
      if (layerRenderer.prepareFrame(frameState)) {
        canvas = layerRenderer.renderFrame(frameState);
      }
    }
    return canvas;
  }
@param {import("../Map").FrameState} frameState Frame state.
@param {Array<SourceType>} sources Sources.
@return {HTMLElement} Canvas.