Fix test failure under Python 2.7.
diff --git a/libcloud/test/storage/test_base.py b/libcloud/test/storage/test_base.py
index 358aacd..24c741a 100644
--- a/libcloud/test/storage/test_base.py
+++ b/libcloud/test/storage/test_base.py
@@ -263,12 +263,12 @@
iterator = BodyStream('b' * size)
iterator.seek = mock.Mock(side_effect=seek_error)
- self.assertRaisesRegex(OSError, 'Other error',
- self.driver1._upload_object,
- object_name='test1',
- content_type=None,
- request_path='/',
- stream=iterator)
+ assertRaisesRegex(self, OSError, 'Other error',
+ self.driver1._upload_object,
+ object_name='test1',
+ content_type=None,
+ request_path='/',
+ stream=iterator)
if __name__ == '__main__':
