Yes makes sense.  If one really wants side effects in a Java Repo module the below will do it.

Looking forward to the custom lib feature and lib/custom seems a good name to me.

Thanks

/Andy

---------------------
package org.basex.modules;

public class Hello {

    private String str = "BaseX";

    public Hello() {}

    public void setDefault(String str) {
        this.str = str;
    }

    public String hello(final String world) {
        return "Hello " + world;
    }

    public String hello() {
        return "Hello " + str;
    }
}
-------------------------------
import module namespace t='org.basex.modules.Hello';
t:setDefault("my default"),
t:hello()