private Tuple2<String, Option<CNode>> configureMapping(CNode config) {
        Mapping mapping = unchecked(config::asMapping).apply();
        if (mapping.size() != 1) {
            throw new IllegalArgumentException("Single entry map expected to configure a " + target.getName());
        } else {
            Map.Entry<String, CNode> next = mapping.entrySet().iterator().next();
            return Tuple.of(next.getKey(), Option.some(next.getValue()));
        }
    }
Matches suitable descriptors for the target.
The fetch is trivial when the target implements a root {@link Describable} object.
If not, we iterate to parent classes until we find a class which can provide the descriptor list in {@link Jenkins#getDescriptorList(Class)}.
Then we go through all the descriptors and find ones compliant with the target.
@return Stream of descriptors which match the target
plugin/src/main/java/io/jenkins/plugins/casc/impl/configurators/HeteroDescribableConfigurator.java