code: public static <T> Flux<T> defer(Supplier<? extends Publisher<T>> supplier) {
  		return onAssembly(new FluxDefer<>(supplier));
  	}
docs: Lazily supply a {@link Publisher} every time a {@link Subscription} is made on the
  resulting {@link Flux}, so the actual source instantiation is deferred until each
  subscribe and the {@link Supplier} can create a subscriber-specific instance.
  If the supplier doesn't generate a new instance however, this operator will
  effectively behave like {@link #from(Publisher)}.
  
  <p>
  <img class="marble" src="doc-files/marbles/deferForFlux.svg" alt="">
  
  @param supplier the {@link Publisher} {@link Supplier} to call on subscribe
  @param <T>      the type of values passing through the {@link Flux}
  
  @return a deferred {@link Flux}