code: @SuppressWarnings("unchecked")
      public <U> FutureStream<U> from(final Iterator<U> iterator) {
          return fromStream(StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, Spliterator.ORDERED), false));
  
      }
docs: Start a reactive flow from a JDK Iterator
  <pre>
  {@code
  Iterator<Integer> iterator;
  new LazyReact(10,10).from(iterator)
  .map(this::process);
  
  }
  </pre>
  @param iterator SimpleReact will iterate over this iterator concurrently to skip the reactive dataflow
  @return  FutureStream