new_contents: import wget
  import optparse
  import os
  
  
  class UpgradeCeph(object):
      '''
          Tool to Upgrade ODL
      '''
  
      def __init__(self):
          self.parser = self._get_opt_parser()
          cls = UpgradeCeph
          cls.options, cls.arguments = self.parser.parse_args()
  
          if self.prelim_checks(cls.options.old_dir, cls.options.new_dir,
                                cls.options.odl_url):
              try:
                  self.wget_url(cls.options.odl_url)
              except:
                  # upgrade_odl()
                  pass
  
      def wget_url(odl_url):
          pass
  
      def prelim_checks(self, old_dir, new_dir, odl_url):
          if old_dir is None or new_dir is None or odl_url is None:
              return False
  
          for dirpath, dirnames, files in os.walk(old_dir):
                  if not files:
                      return False
  
          for dirpath, dirnames, files in os.walk(new_dir):
                  if files:
                      print 'new_dir not empty.'
  
      def _get_opt_parser(self):
          desc = ('Command line parser for Upgrade ODL \n')
  
          parser = optparse.OptionParser(description=desc)
          parser.add_option('-o', '--old_dir', dest='old_dir', default=None)
          parser.add_option('-n', '--new_dir', dest='new_dir', default=None)
          parser.add_option('-u', '--odl_url', dest='odl_url', default=None)
          return parser
  
subject: Add run.py and prelim_checks