### Description There is currently no way to set the filename for parts in `MultipartFormDataOutput` for resteasy-reactive. [Here](https://github.com/quarkusio/quarkus/blob/164856adf64af36122b3b45fd35526274cf41ff9/independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/multipart/MultipartFormDataOutput.java) is the corresponding code. ### Implementation ideas Either add a method ```java // or void public PartItem addFormData(String key, PartItem entity) ``` or ```java public PartItem addFormData(String key, Object entity, MediaType mediaType, String filename) ```