Method strftime

Lib/test/datetimetester.py:1659–1660

(self, format_spec)

        # check that a derived class's strftime gets called
        class B(self.theclass):
            def strftime(self, format_spec):
                return 'B'
        b = B(2007, 9, 10)
        self.assertEqual(b.__format__(''), str(dt))