def _ensure_exists(name, path=None):
 if (not exists(name, path=path)):
  raise CommandExecutionError("Container '{0}' does not exist".format(name))

def _ensure_exists ( name , path = None ) : if ( not exists ( name , path = path ) ) : raise CommandExecutionError ( "Container '{0}' does not exist" . format ( name ) )
decorator to ensure that the named container exists .