Remove unused private method.

kombu/connection.py

@@ -452,10 +452,6 @@ class Connection(object):
             self.maybe_close_channel(self._default_channel)
             self._default_channel = None
 
-    def _default_ensure_callback(self, exc, interval):
-        logger.error("Ensure: Operation error: %r. Retry in %ss",
-                     exc, interval, exc_info=True)
-
     def ensure(self, obj, fun, errback=None, max_retries=None,
                interval_start=1, interval_step=1, interval_max=1,
                on_revive=None):

t/unit/test_connection.py

@@ -218,12 +218,6 @@ class test_Connection:
         c = Connection('pyamqp+sqlite://some_host')
         assert c.as_uri().startswith('pyamqp+')
 
-    def test_default_ensure_callback(self):
-        with patch('kombu.connection.logger') as logger:
-            c = Connection(transport=Mock)
-            c._default_ensure_callback(KeyError(), 3)
-            logger.error.assert_called()
-
     def test_ensure_connection_on_error(self):
         c = Connection('amqp://A;amqp://B')
         with patch('kombu.connection.retry_over_time') as rot: