src/vs/base/common/worker/simpleWorker.ts/SimpleWorkerServer/_handleEvent
class SimpleWorkerServer:	private _handleEvent(eventName: string, arg: any): Event<any> {
		if (!this._requestHandler) {
			throw new Error(`Missing requestHandler`);
		}
		if (propertyIsDynamicEvent(eventName)) {
			const event = (this._requestHandler as any)[eventName].call(this._requestHandler, arg);
			if (typeof event !== 'function') {
				throw new Error(`Missing dynamic event ${eventName} on request handler.`);
			}
			return event;
		}
		if (propertyIsEvent(eventName)) {
			const event = (this._requestHandler as any)[eventName];
			if (typeof event !== 'function') {
				throw new Error(`Missing event ${eventName} on request handler.`);
			}
			return event;
		}
		throw new Error(`Malformed event name ${eventName}`);
	}