buildbucket: add retry API.

appengine/cr-buildbucket/test/service_test.py

Index: appengine/cr-buildbucket/test/service_test.py
diff --git a/appengine/cr-buildbucket/test/service_test.py b/appengine/cr-buildbucket/test/service_test.py
index af7fe94c1dbea5960094b52d933a538ca03f3aea..ebb7a4ebaf0c0937c8ea523ea5823fd0b8c780be 100644
--- a/appengine/cr-buildbucket/test/service_test.py
+++ b/appengine/cr-buildbucket/test/service_test.py
@@ -109,6 +109,22 @@ class BuildBucketServiceTest(testing.AppengineTestCase):
     with self.assertRaises(errors.InvalidInputError):
       service.add('bucket', parameters=[])
 
+  ################################### RETRY ####################################
+
+  def test_retry(self):
+    self.test_build.put()
+    build = service.retry(self.test_build.key.id())
+    self.assertIsNotNone(build)
+    self.assertIsNotNone(build.key)
+    self.assertNotEqual(build.key.id(), self.test_build.key.id())
+    self.assertEqual(build.bucket, self.test_build.bucket)
+    self.assertEqual(build.parameters, self.test_build.parameters)
+    self.assertIn('retry_of:%s' % self.test_build.key.id(), build.tags)
+
+  def test_retry_not_found(self):
+    with self.assertRaises(errors.BuildNotFoundError):
+      service.retry(2)
+
   #################################### GET #####################################
 
   def test_get(self):