code: def _clear(cls):
          
          cls._default_depot = None
          cls._depots = {}
          cls._middleware = None
          cls._aliases = {}
docs: This is only for testing pourposes, resets the DepotManager status
  
          This is to simplify writing test fixtures, resets the DepotManager global
          status and removes the informations related to the current configured depots
          and middleware.