message: add dispose to PointCloud
diff: @@ -13,16 +13,13 @@ import { RenderPass, RenderOrder } from "./RenderFlags";
  import { Target } from "./Target";
  import { GL } from "./GL";
  import { System } from "./System";
  +import { dispose } from "@bentley/bentleyjs-core";
  export class PointCloudGraphic extends Graphic {
  public readonly args: PointCloudArgs;
  - public addCommands(_commands: RenderCommands): void {
  - }
  - public dispose(): void {
  - }
  - public static create(args: PointCloudArgs) {
  - return new PointCloudGraphic(args);
  - }
  + public addCommands(_commands: RenderCommands): void { }
  + public dispose(): void { }
  + public static create(args: PointCloudArgs) { return new PointCloudGraphic(args); }
  private constructor(args: PointCloudArgs) {
  super();
  @@ -33,6 +30,8 @@ export class PointCloudGeometry extends CachedGeometry {
  private vertices: QBufferHandle3d;
  private vertexCount: number;
  + public dispose() { dispose(this.vertices); }
  +
  constructor(pointCloud: PointCloudArgs) {
  super();
  this.vertices = QBufferHandle3d.create(pointCloud.points.params, pointCloud.points.toTypedArray()) as QBufferHandle3d;
  