public static HttpResponse fromObject(ResponseHeaders headers, @Nullable Object content,
                                          ObjectMapper mapper) {
        return fromObject(headers, content, HttpHeaders.of(), mapper);
    }
Returns a newly created JSON Lines response from the specified {@code content}.

@param headers the HTTP headers supposed to send
@param content the object supposed to send as contents
@param mapper the mapper which converts the content object into JSON Lines
core/src/main/java/com/linecorp/armeria/server/streaming/JsonLines.java