docs: def get_machine_id():
      '''
      Provide the machine-id for machine/virtualization combination
      '''
      # Provides:
      #   machine-id
      if platform.system() == 'AIX':
          return _aix_get_machine_id()
  
      locations = ['/etc/machine-id', '/var/lib/dbus/machine-id']
      existing_locations = [loc for loc in locations if os.path.exists(loc)]
      if not existing_locations:
          return {}
      else:
          with salt.utils.files.fopen(existing_locations[0]) as machineid:
              return {'machine_id': machineid.read().strip()}