@Override
    public List<String> possibleValues() {
        final List<Descriptor> descriptors = Jenkins.get().getDescriptorList(type);
        return descriptors.stream()
                .map(d -> getPreferredSymbol(d, type, d.getKlass().toJavaClass()))
                .collect(Collectors.toList());
    }
@author <a href="mailto:nicolas.deloof@gmail.com">Nicolas De Loof</a>
plugin/src/main/java/io/jenkins/plugins/casc/impl/attributes/DescribableAttribute.java