public static <T> HttpResponse fromStream(Stream<T> contentStream, Executor executor,
                                              Function<? super T, ? extends ServerSentEvent> converter) {
        return fromStream(defaultHttpHeaders, contentStream, HttpHeaders.of(), executor, converter);
    }
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
core/src/main/java/com/linecorp/armeria/server/streaming/ServerSentEvents.java