docs: def set_option_name_2_instance(self, options):
          """{title: {'-a': Option(), '--all': Option()}}"""
          title_opt_2_ins = self.titled_opt_to_ins
          title_opt_2_ins.clear()
          for title, opts in options.items():
              title_opt_2_ins[title] = opt_2_ins = {}
              for each in opts:
                  opt_ins = each[0]  # get Option inside Optional/Required
                  for name in opt_ins.names:
                      opt_2_ins[name] = each