[undertow-dev] Undertow server doesn't support PATCH

I am building a REST API framework on top of undertow core to support design driven implementation from Open API (Swagger) specifications for security and validation during runtime. From swagger-codegen result, I found that undertow doesn't support http method PATCH. Is there a reason it is not supported? or any workaround? Thanks. https://github.com/networknt/undertow-server