code: def add_agent_button(self, team_index: int):
          
          agent = self.load_agent()
          if agent is None:
              return
          agent.set_team(team_index)
          self.car_customisation.update_presets_widgets()
          self.agent_customisation.update_presets_widgets()
          self.update_teams_listwidgets()
          if agent.get_team() == 0:
              self.blue_listwidget.setCurrentItem(self.blue_listwidget.findItems(
                  self.validate_name(agent.get_name(), agent), QtCore.Qt.MatchExactly)[0])
          else:
              self.orange_listwidget.setCurrentItem(self.orange_listwidget.findItems(
                  self.validate_name(agent.get_name(), agent), QtCore.Qt.MatchExactly)[0])
docs: The method to handle the [+] button press, adds an agent to the team
          :param team_index: the team to set for the new agent, 0 for blue and 1 for orange
          :return: