code: @Nullable
  	public final T blockLast() {
  		BlockingLastSubscriber<T> subscriber = new BlockingLastSubscriber<>();
  		Operators.onLastAssembly(this).subscribe(Operators.toCoreSubscriber(subscriber));
  		return subscriber.blockingGet();
  	}
docs: Subscribe to this {@link Flux} and <strong>block indefinitely</strong>
  until the upstream signals its last value or completes. Returns that value,
  or null if the Flux completes empty. In case the Flux errors, the original
  exception is thrown (wrapped in a {@link RuntimeException} if it was a checked
  exception).
  <p>
  Note that each blockLast() will trigger a new subscription: in other words,
  the result might miss signal from hot publishers.
  
  <p>
  <img class="marble" src="doc-files/marbles/blockLast.svg" alt="">
  
  @return the last value or null