gearman java service jar is missing the main class necessary to support java -jar

the description on the page http://gearman.org/java-gearman-service/ describes the possibility to run the server as a runnable jar with java -jar, however this code is missing in the source and it would require a pom rule to build a shaded jar with Main-Class attribute.

(or at least I didn't find the code for a main method)