code: def install_os_snaps(snaps, refresh=False):
      
  
      def _ensure_flag(flag):
          if flag.startswith('--'):
              return flag
          return '--{}'.format(flag)
  
      if refresh:
          for snap in snaps.keys():
              snap_refresh(snap,
                           _ensure_flag(snaps[snap]['channel']),
                           _ensure_flag(snaps[snap]['mode']))
      else:
          for snap in snaps.keys():
              snap_install(snap,
                           _ensure_flag(snaps[snap]['channel']),
                           _ensure_flag(snaps[snap]['mode']))
docs: Install OpenStack snaps from channel and with mode
  
      @param snaps: Dictionary of snaps with channels and modes of the form:
          {'snap_name': {'channel': 'snap_channel',
                         'mode': 'snap_mode'}}
          Where channel is a snapstore channel and mode is --classic, --devmode
          or --jailmode.
      @param post_snap_install: Callback function to run after snaps have been
      installed