code: public static <T, S> Flux<T> generate(Callable<S> stateSupplier, BiFunction<S, SynchronousSink<T>, S> generator) {
  		return onAssembly(new FluxGenerate<>(stateSupplier, generator));
  	}
docs: Programmatically create a {@link Flux} by generating signals one-by-one via a
  consumer callback and some state. The {@code stateSupplier} may return {@literal null}.
  <p>
  <img class="marble" src="doc-files/marbles/generate.svg" alt="">
  
  @param <T> the value type emitted
  @param <S> the per-subscriber custom state type
  @param stateSupplier called for each incoming Subscriber to provide the initial state for the generator bifunction
  @param generator Consume the {@link SynchronousSink} provided per-subscriber by Reactor
  as well as the current state to generate a <strong>single</strong> signal on each pass
  and return a (new) state.
  @return a {@link Flux}