code: def manage_async(self, command='', name='process', site=ALL, exclude_sites='', end_message='', recipients=''):
          
          exclude_sites = exclude_sites.split(':')
          r = self.local_renderer
          for _site, site_data in self.iter_sites(site=site, no_secure=True):
              if _site in exclude_sites:
                  continue
              r.env.SITE = _site
              r.env.command = command
              r.env.end_email_command = ''
              r.env.recipients = recipients or ''
              r.env.end_email_command = ''
              if end_message:
                  end_message = end_message + ' for ' + _site
                  end_message = end_message.replace(' ', '_')
                  r.env.end_message = end_message
                  r.env.end_email_command = r.format('{manage_cmd} send_mail --subject={end_message} --recipients={recipients}')
              r.env.name = name.format(**r.genv)
              r.run(
                  'screen -dmS {name} bash -c "export SITE={SITE}; '\
                  'export ROLE={ROLE}; cd {project_dir}; '\
                  '{manage_cmd} {command} --traceback; {end_email_command}"; sleep 3;')
docs: Starts a Django management command in a screen.
  
          Parameters:
  
              command :- all arguments passed to `./manage` as a single string
  
              site :- the site to run the command for (default is all)
  
          Designed to be ran like:
  
              fab <role> dj.manage_async:"some_management_command --force"