old_contents: from .constants import (OK, NOT_OK, DUNNO)
  from .baseplugin import BasePlugin
  from .basedbusplugin import BaseDbusPlugin
  from .logindsessions import LogindSessions
  from .logindinhibitors import LogindInhibitors
  from .processes import Processes
  from .processeswithconnections import ProcessesWithConnections
  
new_contents: from .constants import (OK, NOT_OK, DUNNO)
  from .baseplugin import BasePlugin
  from .basedbusplugin import BaseDbusPlugin
  from .logindsessions import LogindSessions
  from .logindinhibitors import LogindInhibitors
  from .processes import Processes
  from .processeswithconnections import ProcessesWithConnections
  from .noshutdownfile import NoShutdownFile
  
subject: add plugin for a "noshutdown" file