#NEWLINE# def assertFileDoesNotExist( self , name ) : #NEWLINE# #INDENT# self . content . seek ( 0 ) #NEWLINE# with tarfile . open ( fileobj = self . content , mode = 'r' ) as tar : #NEWLINE# #INDENT# assert ( self not in tar . getnames ( ) ) , ( 'File %s was found in the container files: %s' % ( name , tar . getnames ( ) ) )