old_contents: 
  
  class Dev(object):
  
      help = "Development options"
  
      def __init__(self, arguments):
          self.arguments = arguments
  
      def main(self):
          raise SystemExit(0)
  
new_contents: from os import path
  from textwrap import dedent
  from tambo import Transport
  
  from ceph_installer import process
  from ceph_installer.cli import log
  
  this_dir = path.abspath(path.dirname(__file__))
  top_dir = path.dirname(path.dirname(this_dir))
  playbook_path = path.join(top_dir, 'deploy/playbooks')
  
  
  class Dev(object):
  
      help = "Development options"
      options = ['--user', '--branch']
      _help = dedent("""
      Deploying the ceph-installer HTTP service to a remote server with ansible.
      This command wraps ansible and certain flags to make it easier to deploy
      a development version.
  
      Usage::
  
          ceph-installer dev $HOST
  
      Note: Requires a remote user with passwordless sudo. User defaults to
      "vagrant".
  
      Options:
  
      --user        Define a user to connect to the remote server. Defaults  to 'vagrant'
      --branch      What branch to use for the deployment. Defaults to 'master'
      -vvvv         Enable high verbosity when running ansible
      """)
  
      def __init__(self, arguments):
          self.arguments = arguments
  
      def main(self):
          parser = Transport(self.arguments, options=self.options, check_help=True)
          parser.catch_help = self._help
          parser.parse_args()
          parser.catches_help()
          branch = parser.get('branch', 'master')
          user = parser.get('user', 'vagrant')
          high_verbosity = '-vvvv' if parser.has('-vvvv') else '-v'
          if not parser.unknown_commands:
              log.error("it is required to pass a host to deploy to, but none was provided")
              raise SystemExit(1)
  
          command = [
              "ansible-playbook",
              "-i", "%s," % parser.unknown_commands[-1],
              high_verbosity,
              "-u", user,
              "--extra-vars", '"branch=%s"' % branch,
              "deploy.yml",
          ]
          log.debug("Running command: %s" % ' '.join(command))
          out, err, code = process.run(command, cwd=playbook_path)
          log.error(err)
          log.debug(out)
  
subject: create a working dev sub-command