code: public final Flux<List<T>> buffer(Duration bufferingTimespan, Scheduler timer) {
  		return buffer(interval(bufferingTimespan, timer));
  	}
docs: Collect incoming values into multiple {@link List} buffers that will be emitted by
  the returned {@link Flux} every {@code bufferingTimespan}, as measured on the provided {@link Scheduler}.
  <p>
  <img class="marble" src="doc-files/marbles/bufferWithTimespan.svg" alt="">
  
  @reactor.discard This operator discards the currently open buffer upon cancellation or error triggered by a data signal.
  
  @param bufferingTimespan the duration from buffer creation until a buffer is closed and emitted
  @param timer a time-capable {@link Scheduler} instance to run on
  
  @return a microbatched {@link Flux} of {@link List} delimited by the given period