message: Added is3d method to DisplayStyleState, this mimics the behavior of the ViewState is3d
diff: @@ -41,6 +41,8 @@ export abstract class DisplayStyleState extends ElementState {
  public getMonochromeColor(): ColorDef { return ColorDef.fromJSON(this.getStyle("monochromeColor")); }
  public setMonochromeColor(val: ColorDef): void { this.setStyle("monochromeColor", val); }
  +
  + public is3d(): this is DisplayStyle3dState { return this instanceof DisplayStyle3dState; }
  }
  /** A DisplayStyle for 2d views */
  