old_contents: import argparse
  
  from psi.application import (add_default_options, launch_experiment,
                               parse_args)
  from psi.application.experiment_description import experiments
  
  
  def main():
      class ControllerAction(argparse.Action):
          def __call__(self, parser, namespace, value, option_string=None):
              setattr(namespace, 'experiment', value)
              setattr(namespace, 'controller', experiments[value])
              for plugin in experiments[value].plugins:
                  plugin.selected = False
  
      class PluginAction(argparse.Action):
          def __call__(self, parser, namespace, value, option_string=None):
              for plugin_name in value:
                  namespace.controller.enable_plugin(plugin_name)
  
  
      parser = argparse.ArgumentParser(description='Run experiment')
      parser.add_argument('experiment', type=str, help='Experiment to run',
                          choices=experiments.keys(), action=ControllerAction)
      parser.add_argument('--plugins', type=str, nargs='*',
                          help='Plugins to load', action=PluginAction)
  
      add_default_options(parser)
      args = parse_args(parser)
      launch_experiment(args)
  
new_contents: import argparse
  
  from psi.application import (add_default_options, launch_experiment,
                               parse_args)
  from psi.application.experiment_description import experiments
  
  
  def main():
      class ControllerAction(argparse.Action):
          def __call__(self, parser, namespace, value, option_string=None):
              setattr(namespace, 'experiment', value)
              setattr(namespace, 'controller', experiments[value])
              for plugin in experiments[value].plugins:
                  plugin.selected = False
  
      class PluginAction(argparse.Action):
          def __call__(self, parser, namespace, value, option_string=None):
              for plugin_name in value:
                  namespace.controller.enable_plugin(plugin_name)
  
      parser = argparse.ArgumentParser(description='Run experiment')
      parser.add_argument('experiment', type=str, help='Experiment to run',
                          choices=experiments.keys(), action=ControllerAction)
      parser.add_argument('--plugins', type=str, nargs='*',
                          help='Plugins to load', action=PluginAction)
  
      add_default_options(parser)
      args = parse_args(parser)
      launch_experiment(args)
  
subject: Remove whitespace