#17564: skip test_bad_address unless the tests are run with -unetwork/-uall.
#17526: fix an IndexError raised while passing code without filename to inspect.findsource().  Initial patch by Tyler Doyle.
#17539: fix MagicMock example.  Patch by Berker Peksag.
Updated logging cookbook with additional example for output using str.format().
Issue #17435: Don't use mutable default values in Timer.

Patch by Denver Coneybeare with some test modifications by me.