rule "Init"
    dialect "mvel"
    when
        $fl: FactWithList(items.size()==0)
    then
        $fl.getItems().add("A");
        $fl.getItems().add("B");
        update($fl);
end

rule "Expected Outcome"
    dialect "mvel"
    when
        $fl: FactWithList($itemList : items != null)
        $l: java.util.ArrayList(size > 0) from collect(FactWithString($itemList contains stringValue));
    then
        System.out.println("--> Rule: " + kcontext.getRule().getName() + " fired, " + $fl + ", collect list: " + $l.size());
end