Shivank, indeed it seems you're now in the right direction.A bit of clarification:* The test shouldn't test _clone_node() directly, since that is an internal function.  Rather, the test code should be as near as possible to what a user of the minidom module would reasonably write.* Since this bug appears in two places, you'll likely need different tests for each of them.  You should likely start with just one, and once you've successfully written a test for it and fixed it, move on to the other.  (In the end, make each test+fix a separate commit in the PR.)