Verify the specified scenario was found and returns None.

        :return: None

def _verify(self):
        """
        Verify the specified scenario was found and returns None.

        :return: None
        """
        scenario_names = [c.scenario.name for c in self._configs]
        if self._scenario_name not in scenario_names:
            msg = ("Scenario '{}' not found.  "
                   'Exiting.').format(self._scenario_name)
            util.sysexit_with_message(msg)