method AsyncResult.prototype.then AsyncResult.prototype.then<TResult1 = Result<T, E>, TResult2 = never>(onfulfilled?: ((value: Result<T, E>) => TResult1 | PromiseLike<TResult1>) | null,onrejected?: ((reason: unknown) => TResult2 | PromiseLike<TResult2>) | null): Promise<TResult1 | TResult2> Implements PromiseLike to make AsyncResult awaitable. Type Parameters TResult1 = Result<T, E> The type when fulfilled TResult2 = never The type when rejected Parameters optional onfulfilled: ((value: Result<T, E>) => TResult1 | PromiseLike<TResult1>) | null Callback for when the promise is fulfilled optional onrejected: ((reason: unknown) => TResult2 | PromiseLike<TResult2>) | null Callback for when the promise is rejected Return Type Promise<TResult1 | TResult2> A Promise of the result