message: GeometryListBuilder, dont redefine isOpen, dont check accum for undef
diff: @@ -328,7 +328,6 @@ export class GeometryAccumulator {
  export abstract class GeometryListBuilder extends GraphicBuilder {
  public accum: GeometryAccumulator;
  public graphicParams: GraphicParams = new GraphicParams();
  - protected _isOpen: boolean = false;
  public abstract finishGraphic(accum: GeometryAccumulator): RenderGraphic; // Invoked by _Finish() to obtain the finished RenderGraphic.
  @@ -338,7 +337,7 @@ export abstract class GeometryListBuilder extends GraphicBuilder {
  }
  public _finish(): RenderGraphic | undefined {
  - if (!this.isOpen || !this.accum) {
  + if (!this.isOpen) {
  assert(false);
  return undefined;
  }
  