#NEWLINE# def test_noDuplicateAddsResult( self ) : #NEWLINE# #INDENT# '\n        If a destination has already been added, calling L{redirectLogsForTrial}\n        a second time returns L{None}.\n        ' #NEWLINE# redirect = _RedirectLogsForTrial ( FakeSys ( [ 'trial' ] , b'' ) , LogPublisher ( ) ) #NEWLINE# destination = redirect ( ) #NEWLINE# self . addCleanup ( removeDestination , self ) #NEWLINE# result = redirect ( ) #NEWLINE# self . assertIs ( result , None )