Remove unused import
diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
index 786bb41..ef19641 100644
--- a/Lib/test/test_signal.py
+++ b/Lib/test/test_signal.py
@@ -1,6 +1,6 @@
 import unittest
 from test import support
-from contextlib import closing, nested
+from contextlib import closing
 import gc
 import pickle
 import select