def test_absent(self):
     class A(object):
         pass
     with self.assertRaises(AttributeError):
         _get_method_from_class(A, 'do_something')
 def test_is_not_method(self):
     class A(object):
         do_something = False
     with self.assertRaises(TypeError):
         _get_method_from_class(A, 'do_something')
 def test_exists(self):
     class A(object):
         def do_something(self):
             pass
     self.assertEqual(A.do_something,
                      _get_method_from_class(A, 'do_something'))