question: see ratpack.stream.streams #buffer publisher . concode_field_sep PlaceHolder placeHolder concode_field_sep TransformablePublisher<O> flatMap concode_elem_sep TransformablePublisher<T> filter concode_elem_sep TransformablePublisher<O> transform concode_elem_sep TransformablePublisher<O> streamMap concode_elem_sep TransformablePublisher<T> wiretap concode_elem_sep TransformablePublisher<T> gate concode_elem_sep Promise<List<T>> toList concode_elem_sep TransformablePublisher<O> map concode_elem_sep TransformablePublisher<T> multicast concode_elem_sep Promise<T> toPromise
target: TransformablePublisher < T > function ( ) { return Streams . buffer ( this ) ; }