flatThen
override fun <R : ERROR CLASS: Symbol not found for JsAny??> flatThen(onFulfilled: (T) -> PromiseResult<R>): Promise<R>(source)
override fun <R : ERROR CLASS: Symbol not found for JsAny??> flatThen(onFulfilled: (T) -> PromiseResult<R>, onRejected: (JsErrorLike?) -> PromiseResult<R>): Promise<R>(source)