Remove unused or redundant imports in concurrent.futures and multiprocessing.
diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py
index 5a57288..f42d353 100644
--- a/Lib/multiprocessing/managers.py
+++ b/Lib/multiprocessing/managers.py
@@ -39,19 +39,15 @@
# Imports
#
-import os
import sys
-import weakref
import threading
import array
import queue
from traceback import format_exc
-from pickle import PicklingError
from multiprocessing import Process, current_process, active_children, Pool, util, connection
from multiprocessing.process import AuthenticationString
-from multiprocessing.forking import exit, Popen, assert_spawning, ForkingPickler
-from multiprocessing.util import Finalize, info
+from multiprocessing.forking import exit, Popen, ForkingPickler
#
# Register some things for pickling