doc string added

theano/tensor/tests/test_opt.py

@@ -6201,7 +6201,6 @@ class Test_local_useless_reshape(unittest.TestCase):
                                   "TensorConstant{[5 6]}))]")
 
         # Check stacktrace was copied over correctly after opt was applied
-        self.assertTrue(hasattr(g.outputs[0].tag, 'trace'))
         check_stack_trace(g, ops_to_check=(T.DimShuffle, T.Reshape))