StreamClass.find<S>(source: Source<S>,predicate: (value: Exclude<S, AnyFailure>,index: number) => boolean | PromiseLike<boolean>): Task<Exclude<S, AnyFailure> | undefined, Extract<S, AnyFailure>>
StreamClass#find as a static: Stream.find(source, …) is
Stream.from(source).find(…).
await Stream.find([1, 2], (n) => n > 1); // 2