src/vs/base/parts/ipc/common/ipc.ts/responseTypeToStr
function responseTypeToStr(type: ResponseType): string {
	switch (type) {
		case ResponseType.Initialize:
			return `init`;
		case ResponseType.PromiseSuccess:
			return `reply:`;
		case ResponseType.PromiseError:
		case ResponseType.PromiseErrorObj:
			return `replyErr:`;
		case ResponseType.EventFire:
			return `event:`;
	}
}