Drop unused import in unittest package.
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index cc5f0c3..5bed868 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -9,8 +9,7 @@
import collections
from . import result
-from .util import (strclass, safe_repr, sorted_list_difference,
- unorderable_list_difference, _count_diff_all_purpose,
+from .util import (strclass, safe_repr, _count_diff_all_purpose,
_count_diff_hashable)
__unittest = True
diff --git a/Lib/unittest/main.py b/Lib/unittest/main.py
index 55d4e4b..c50066f 100644
--- a/Lib/unittest/main.py
+++ b/Lib/unittest/main.py
@@ -2,7 +2,6 @@
import sys
import os
-import types
from . import loader, runner
from .signals import installHandler
diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
index 44bf186..97e5426 100644
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -1,6 +1,5 @@
"""Test result object"""
-import os
import io
import sys
import traceback
diff --git a/Lib/unittest/test/_test_warnings.py b/Lib/unittest/test/_test_warnings.py
index d0be18d..5cbfb53 100644
--- a/Lib/unittest/test/_test_warnings.py
+++ b/Lib/unittest/test/_test_warnings.py
@@ -10,7 +10,6 @@
See #10535.
"""
-import io
import sys
import unittest
import warnings