code: public static <T> HttpResponse fromPublisher(HttpHeaders headers,
                                                   Publisher<T> contentPublisher,
                                                   HttpHeaders trailingHeaders,
                                                   Function<? super T, ? extends ServerSentEvent> converter) {
          requireNonNull(headers, "headers");
          requireNonNull(contentPublisher, "contentPublisher");
          requireNonNull(trailingHeaders, "trailingHeaders");
          requireNonNull(converter, "converter");
          return streamingFrom(contentPublisher, sanitizeHeaders(headers), trailingHeaders,
                               o -> toHttpData(converter, o));
      }
docs: Creates a new Server-Sent Events stream from the specified {@link Publisher} and {@code converter}.
  
  @param headers the HTTP headers supposed to send
  @param contentPublisher the {@link Publisher} which publishes the objects supposed to send as contents
  @param trailingHeaders the trailing HTTP headers supposed to send
  @param converter the converter which converts published objects into {@link ServerSentEvent}s