private Stream<String> getSymbols(Descriptor<T> descriptor) {
        return Stream.ofAll(DescribableAttribute.getSymbols(descriptor, target, target));
    }
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