[keycloak-user] Extending Themes via SPI

Hi all, In regards to Extending Themes via SPI all I found is this documentation: http://keycloak.github.io/docs/userguide/keycloak-server/html/providers.html and <http://keycloak.github.io/docs/userguide/keycloak-server/html/themes.html... http://keycloak.github.io/docs/userguide/keycloak-server/html/themes.html... I found it a little less describing. When I implement those two classes, where do I put the new implemented classes? How do I deploy them? Can I also use Spring mvc and JSP and few maven dependencies instead of freemarker? I also tried to find an example to extend theme using SPI but there seems to be none. It would be really nice if you could provide a sample hello world. Thank you very much, Sarp Kaya