code: public static <T> Flux<T> from(Publisher<? extends T> source) {
  		if (source instanceof Flux) {
  			@SuppressWarnings("unchecked")
  			Flux<T> casted = (Flux<T>) source;
  			return casted;
  		}
  
  		if (source instanceof Fuseable.ScalarCallable) {
  			try {
  				@SuppressWarnings("unchecked") T t =
  						((Fuseable.ScalarCallable<T>) source).call();
  				if (t != null) {
  					return just(t);
  				}
  				return empty();
  			}
  			catch (Exception e) {
  				return error(e);
  			}
  		}
  		return wrap(source);
  	}
docs: Decorate the specified {@link Publisher} with the {@link Flux} API.
  <p>
  <img class="marble" src="doc-files/marbles/fromForFlux.svg" alt="">
  
  @param source the source to decorate
  @param <T> The type of values in both source and output sequences
  
  @return a new {@link Flux}