code: def str_to_application_class(self, an_app_key):
          
          try:
              app_class = str_to_python_object(self.apps[an_app_key])
          except KeyError:
              app_class = str_to_python_object(an_app_key)
          try:
              self.application_defaults = DotDict(
                  app_class.get_application_defaults()
              )
          except AttributeError:
              # no get_application_defaults, skip this step
              pass
          return app_class
docs: a configman compatible str_to_* converter