Test failure: j11_dtests_large.replace_address_test.TestReplaceAddress

assert 0 == 1
 +  where 0 = len(set())
self = <replace_address_test.TestReplaceAddress object at 0x7f390285a8d0>

    @pytest.mark.resource_intensive
    def test_replace_first_boot(self):
>       self._test_replace_node(jvm_option='replace_address_first_boot')

replace_address_test.py:281: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
replace_address_test.py:300: in _test_replace_node
    previous_log_size = self._verify_tokens_migrated_successfully()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <replace_address_test.TestReplaceAddress object at 0x7f390285a8d0>
previous_log_size = None

    def _verify_tokens_migrated_successfully(self, previous_log_size=None):
        if not self.dtest_config.use_vnodes:
            num_tokens = 1
        else:
            # a little hacky but grep_log returns the whole line...
            num_tokens = int(self.replacement_node.get_conf_option('num_tokens'))
    
        logger.debug("Verifying {} tokens migrated successfully".format(num_tokens))
        replmnt_address = self.replacement_node.address_for_current_version_slashy()
        repled_address = self.replaced_node.address_for_current_version_slashy()
        token_ownership_log = r"Token (.*?) changing ownership from {} to {}".format(repled_address,
                                                                                     replmnt_address)
        logs = self.replacement_node.grep_log(token_ownership_log)
    
        if (previous_log_size is not None):
            assert len(logs) == previous_log_size
    
        moved_tokens = set([l[1].group(1) for l in logs])
        logger.debug("number of moved tokens: {}".format(len(moved_tokens)))
>       assert len(moved_tokens) == num_tokens
E       assert 0 == 1
E        +  where 0 = len(set())

replace_address_test.py:207: AssertionError