Import unittest2 in locks_test if needed.

diff --git a/tornado/test/locks_test.py b/tornado/test/locks_test.py
index 73f0f5911fb2105b5c03804f0438d381fbd691ab..d1c9a61d8c3b0363cedd8ef7931246ab89be26aa 100644 (file)
--- a/tornado/test/locks_test.py
+++ b/tornado/test/locks_test.py
@@ -11,11 +11,11 @@
 # under the License.
 
 from datetime import timedelta
-import unittest
 
 from tornado import gen, locks
 from tornado.gen import TimeoutError
 from tornado.testing import gen_test, AsyncTestCase
+from tornado.test.util import unittest
 
 
 class ConditionTest(AsyncTestCase):