code: public final <A> Mono<A> reduce(A initial, BiFunction<A, ? super T, A> accumulator) {
  		return reduceWith(() -> initial, accumulator);
  	}
docs: Reduce the values from this {@link Flux} sequence into a single object matching the
  type of a seed value. Reduction is performed using a {@link BiFunction} that
  takes the intermediate result of the reduction and the current value and returns
  the next intermediate value of the reduction. First element is paired with the seed
  value, {@literal initial}.
  
  <p>
  <img class="marble" src="doc-files/marbles/reduce.svg" alt="">
  
  @reactor.discard This operator discards the internally accumulated value upon cancellation or error.
  
  @param accumulator the reducing {@link BiFunction}
  @param initial the seed, the initial leftmost argument to pass to the reducing {@link BiFunction}
  @param <A> the type of the seed and the reduced object
  
  @return a reduced {@link Flux}