docs: def extra_prepare(self, configuration, args_dict):
          """
          Called before the configuration.converters are activated
  
          Here we make sure that we have harpoon options from ``args_dict`` in
          the configuration.
  
          We then load all the harpoon modules as specified by the
          ``harpoon.addons`` setting.
  
          Finally we inject into the configuration:
  
          $@
              The ``harpoon.extra`` setting
  
          bash
              The ``bash`` setting
  
          command
              The ``command`` setting
  
          harpoon
              The harpoon settings
  
          collector
              This instance
          """
          harpoon = self.find_harpoon_options(configuration, args_dict)
          self.register = self.setup_addon_register(harpoon)
  
          # Make sure images is started
          if "images" not in self.configuration:
              self.configuration["images"] = {}
  
          # Add our special stuff to the configuration
          self.configuration.update(
              { "$@": harpoon.get("extra", "")
              , "bash": args_dict["bash"] or sb.NotSpecified
              , "harpoon": harpoon
              , "assume_role": args_dict["assume_role"] or NotSpecified
              , "command": args_dict['command'] or sb.NotSpecified
              , "collector": self
              }
          , source = "<args_dict>"
          )