code: public static <T> HttpResponse fromStream(Stream<T> contentStream, Executor executor,
                                                Function<? super T, ? extends ServerSentEvent> converter) {
          return fromStream(defaultHttpHeaders, contentStream, HttpHeaders.EMPTY_HEADERS, executor, converter);
      }
docs: Creates a new Server-Sent Events stream from the specified {@link Stream} and {@code converter}.
  
  @param contentStream the {@link Stream} which publishes the objects supposed to send as contents
  @param executor the executor which iterates the stream
  @param converter the converter which converts published objects into {@link ServerSentEvent}s