How to tell the list of classes under a namespace in Laravel

How might I filter through the entire namespace hierarchy to see if my packages have auto-loaded successfully (and for additional processing on those classes)

I have looked for similar questions on SO but none seem to have answered for this specific case.

For example I want to obtain this listing of classes in a Laravel controller, after the whole framework has booted.

I am looking for custom namespaces that I have already autoloaded in composer.json or added to from packages.

CompanyNS\SpecificApplicationNS\Shazbat

How would I go through everything to see what classes have been loaded under Shazbat?

These classes would have been loaded in from other external packages.

Thanks in anticipation.