message: Removing an unused variable
diff: @@ -4,8 +4,6 @@ import { isFunction } from '../util/isFunction';
  import { Subscriber } from '../Subscriber';
  import { map } from '../operators/map';
  -const toString: Function = (() => Object.prototype.toString)();
  -
  export interface NodeStyleEventEmitter {
  addListener: (eventName: string | symbol, handler: NodeEventHandler) => this;
  removeListener: (eventName: string | symbol, handler: NodeEventHandler) => this;
  