code: def populate(self):
          
          self._registry = {}
          
          for provider_class in self._registered_providers:
              instance = provider_class()
              self._registry[instance] = instance.regex
          
          for stored_provider in StoredProvider.objects.active():
              self._registry[stored_provider] = stored_provider.regex
          
          self._populated = True
docs: Populate the internal registry's dictionary with the regexes for each
          provider instance