code: public <U> SimpleReactStream<U> from(final Stream<U> stream) {
  
          final Stream s = stream.map(it -> CompletableFuture.completedFuture(it));
          return construct(s);
      }
docs: Start a reactive dataflow from a stream.
  
  @param stream that will be used to drive the reactive dataflow
  @return Next stage in the reactive flow