code: public function register(Container $pimple)
      {
          $pimple['user'] = function ($pimple) {
              return new User($pimple['access_token']);
          };
  
          $group = function ($pimple) {
              return new Group($pimple['access_token']);
          };
  
          $tag = function ($pimple) {
              return new Tag($pimple['access_token']);
          };
  
          $pimple['user_group'] = $group;
          $pimple['user.group'] = $group;
  
          $pimple['user_tag'] = $tag;
          $pimple['user.tag'] = $tag;
      }
docs: Registers services on the given container.
  
  This method should only be used to configure services and parameters.
  It should not get services.
  
  @param Container $pimple A container instance