[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
diff --git a/examples/fetch-urls b/examples/fetch-urls
index 4cdb95b..77353de 100755
--- a/examples/fetch-urls
+++ b/examples/fetch-urls
@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 """Example script: fetch URLs"""
+
 from __future__ import print_function
 import sys
 import requests
@@ -51,7 +52,7 @@
     # The status code has already been checked on each response.
     # Requests may have been attempted several times if an error occurred.
     for future in as_completed(futures):
-        (url, content) = future.result()
+        url, content = future.result()
         print("=========== %s" % url)
         print(content)
         print("")
diff --git a/more_executors/__init__.py b/more_executors/__init__.py
index c93439d..2d87b62 100644
--- a/more_executors/__init__.py
+++ b/more_executors/__init__.py
@@ -13,6 +13,7 @@
 
 This documentation was built from an unknown revision.
 """
+
 from ._impl.executors import Executors
 from . import futures
 from . import asyncio
diff --git a/more_executors/_impl/common.py b/more_executors/_impl/common.py
index df13431..1a44ccb 100644
--- a/more_executors/_impl/common.py
+++ b/more_executors/_impl/common.py
@@ -87,9 +87,9 @@
 
 def copy_future_exception(f1, f2):
     if "exception_info" in dir(f1):
-        (exception, traceback) = f1.exception_info()
+        exception, traceback = f1.exception_info()
     else:
-        (exception, traceback) = (f1.exception(), None)
+        exception, traceback = (f1.exception(), None)
 
     copy_exception(f2, exception, traceback)
 
diff --git a/more_executors/_impl/futures/apply.py b/more_executors/_impl/futures/apply.py
index c40a457..5d0b07c 100644
--- a/more_executors/_impl/futures/apply.py
+++ b/more_executors/_impl/futures/apply.py
@@ -4,7 +4,6 @@
 from .check import ensure_futures
 from ..metrics import track_future
 
-
 # for wrapping arguments.
 # This value means an argument came from *args rather than **kwargs
 ARGS = object()
@@ -49,7 +48,7 @@
         return wrap(future_fn).with_map(lambda fn: fn())()
 
     future_key_and_x = future_args[0]
-    (key, future_x) = future_key_and_x
+    key, future_x = future_key_and_x
     future_args = future_args[1:]
 
     # future_fn takes multiple arguments.
diff --git a/more_executors/_impl/futures/bool.py b/more_executors/_impl/futures/bool.py
index 13056e6..dd9010d 100644
--- a/more_executors/_impl/futures/bool.py
+++ b/more_executors/_impl/futures/bool.py
@@ -41,7 +41,7 @@
 
             del self.fs[f]
 
-            (set_result, set_exception, cancel_futures) = self.get_state_update(f)
+            set_result, set_exception, cancel_futures = self.get_state_update(f)
 
         if set_result:
             try_set_result(self.out, f.result())
diff --git a/more_executors/_impl/futures/zip.py b/more_executors/_impl/futures/zip.py
index a4e3571..549bb6d 100644
--- a/more_executors/_impl/futures/zip.py
+++ b/more_executors/_impl/futures/zip.py
@@ -12,7 +12,6 @@
 from .check import ensure_futures
 from ..metrics import track_future
 
-
 # For small-ish tuples, we make f_zip return namedtuple instances
 # which can be traced back to here rather than bare tuples. The point
 # is to improve debuggability of code where the future returned by
@@ -41,7 +40,7 @@
         self.lock = Lock()
         self.count_remaining = len(self.fs)
 
-        for (idx, future) in enumerate(self.fs):
+        for idx, future in enumerate(self.fs):
             chain_cancel(self.out, future)
             future.add_done_callback(weak_callback(partial(self.handle_done, idx)))
 
diff --git a/more_executors/_impl/metrics/prometheus.py b/more_executors/_impl/metrics/prometheus.py
index 0769435..8574f6a 100644
--- a/more_executors/_impl/metrics/prometheus.py
+++ b/more_executors/_impl/metrics/prometheus.py
@@ -2,7 +2,6 @@
 
 import prometheus_client  # pylint: disable=import-error
 
-
 Counter = partial(prometheus_client.Counter, namespace="more_executors")
 Gauge = partial(prometheus_client.Gauge, namespace="more_executors")
 
diff --git a/more_executors/_impl/retry.py b/more_executors/_impl/retry.py
index 04bc7fb..6f1e122 100644
--- a/more_executors/_impl/retry.py
+++ b/more_executors/_impl/retry.py
@@ -437,7 +437,7 @@
             self._log.debug("Delegate was cancelled: %s", delegate_future)
             return
 
-        (should_retry, sleep_time) = eval_policy(found_job, self._log)
+        should_retry, sleep_time = eval_policy(found_job, self._log)
 
         if should_retry:
             self._retry(found_job, sleep_time)
diff --git a/more_executors/_impl/throttle.py b/more_executors/_impl/throttle.py
index 3cc8f6b..80de960 100644
--- a/more_executors/_impl/throttle.py
+++ b/more_executors/_impl/throttle.py
@@ -244,6 +244,6 @@
         if not result:
             break
 
-        (event, wait_time) = result
+        event, wait_time = result
         event.wait(wait_time)
         event.clear()
diff --git a/more_executors/_impl/timeout.py b/more_executors/_impl/timeout.py
index 4272af2..b044ef2 100644
--- a/more_executors/_impl/timeout.py
+++ b/more_executors/_impl/timeout.py
@@ -137,7 +137,7 @@
     @executor_loop
     def _job_loop(cls, executor_ref):
         while True:
-            (event, wait_time) = cls._job_loop_iter(executor_ref())
+            event, wait_time = cls._job_loop_iter(executor_ref())
             if not event:
                 break
             event.wait(wait_time)
@@ -156,7 +156,7 @@
         executor._log.debug("job loop")
 
         with executor._jobs_lock:
-            (pending, overdue) = executor._partition_jobs()
+            pending, overdue = executor._partition_jobs()
             executor._jobs = pending
 
         executor._log.debug("jobs: %s overdue, %s pending", len(overdue), len(pending))
diff --git a/more_executors/asyncio.py b/more_executors/asyncio.py
index c60e4e1..12b007c 100644
--- a/more_executors/asyncio.py
+++ b/more_executors/asyncio.py
@@ -1,4 +1,3 @@
 from ._impl.asyncio import AsyncioExecutor
 
-
 __all__ = ["AsyncioExecutor"]
diff --git a/more_executors/cancel_on_shutdown.py b/more_executors/cancel_on_shutdown.py
index 555d835..5060b0b 100644
--- a/more_executors/cancel_on_shutdown.py
+++ b/more_executors/cancel_on_shutdown.py
@@ -1,4 +1,3 @@
 from ._impl.cancel_on_shutdown import CancelOnShutdownExecutor
 
-
 __all__ = ["CancelOnShutdownExecutor"]
diff --git a/more_executors/futures.py b/more_executors/futures.py
index 8627033..472d324 100644
--- a/more_executors/futures.py
+++ b/more_executors/futures.py
@@ -15,7 +15,6 @@
     f_proxy,
 )
 
-
 __all__ = [
     "f_apply",
     "f_or",
diff --git a/more_executors/poll.py b/more_executors/poll.py
index 0389fab..ebb7e8a 100644
--- a/more_executors/poll.py
+++ b/more_executors/poll.py
@@ -1,4 +1,3 @@
 from ._impl.poll import PollExecutor, PollDescriptor
 
-
 __all__ = ["PollExecutor", "PollDescriptor"]
diff --git a/more_executors/sync.py b/more_executors/sync.py
index a791a61..a76ac36 100644
--- a/more_executors/sync.py
+++ b/more_executors/sync.py
@@ -1,4 +1,3 @@
 from ._impl.sync import SyncExecutor
 
-
 __all__ = ["SyncExecutor"]
diff --git a/more_executors/throttle.py b/more_executors/throttle.py
index 7b368ac..a814d84 100644
--- a/more_executors/throttle.py
+++ b/more_executors/throttle.py
@@ -1,4 +1,3 @@
 from ._impl.throttle import ThrottleExecutor
 
-
 __all__ = ["ThrottleExecutor"]
diff --git a/more_executors/timeout.py b/more_executors/timeout.py
index 6a17676..53bb3ca 100644
--- a/more_executors/timeout.py
+++ b/more_executors/timeout.py
@@ -1,4 +1,3 @@
 from ._impl.timeout import TimeoutExecutor
 
-
 __all__ = ["TimeoutExecutor"]
diff --git a/scripts/make-pr b/scripts/make-pr
index 6a0e5c7..86b96ba 100755
--- a/scripts/make-pr
+++ b/scripts/make-pr
@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 """Make a pull request from HEAD"""
+
 from __future__ import print_function
 from argparse import ArgumentParser
 from subprocess import check_call, check_output, Popen, PIPE, CalledProcessError
diff --git a/tests/conftest.py b/tests/conftest.py
index 7252a4d..4025132 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,7 +3,6 @@
 
 import pytest
 
-
 if sys.version_info < (2, 7, 0):
 
     @pytest.fixture
diff --git a/tests/futures/bool_utils.py b/tests/futures/bool_utils.py
index bd93103..1535070 100644
--- a/tests/futures/bool_utils.py
+++ b/tests/futures/bool_utils.py
@@ -2,7 +2,6 @@
 
 from more_executors import f_return, f_return_error, f_return_cancelled
 
-
 CANCELLED = object()
 
 
diff --git a/tests/test_executor.py b/tests/test_executor.py
index 8b99e15..a8297bb 100644
--- a/tests/test_executor.py
+++ b/tests/test_executor.py
@@ -555,11 +555,11 @@
     q2.put(True)
     q2.put(True)
 
-    (done, not_done) = wait(futures, return_when=FIRST_COMPLETED, timeout=TIMEOUT)
+    done, not_done = wait(futures, return_when=FIRST_COMPLETED, timeout=TIMEOUT)
 
     # Might have received 1, or 2
     if len(done) == 1:
-        (more_done, _more_not_done) = wait(
+        more_done, _more_not_done = wait(
             not_done, return_when=FIRST_COMPLETED, timeout=TIMEOUT
         )
         done = done | more_done
@@ -671,7 +671,7 @@
 
         # The timeout here is so that the test fails rather than hangs forever,
         # if something goes wrong.
-        (done, _not_done) = wait(self.futures, 60.0)
+        done, _not_done = wait(self.futures, 60.0)
         assert_that(len(done), equal_to(len(self.futures)))
 
         for f in self.futures:
diff --git a/tests/test_timeout.py b/tests/test_timeout.py
index 62a8a68..9c48a10 100644
--- a/tests/test_timeout.py
+++ b/tests/test_timeout.py
@@ -5,7 +5,6 @@
 
 from more_executors import Executors, TimeoutExecutor
 
-
 TIMEOUT = 0.02
 
 
@@ -56,7 +55,7 @@
         f2 = executor.submit(called.append, True)
         return (f1, f2)
 
-    (f1, f2) = get_futures(Executors.thread_pool(max_workers=1).with_timeout(0.5))
+    f1, f2 = get_futures(Executors.thread_pool(max_workers=1).with_timeout(0.5))
 
     # f2 should be cancelled while f1 was still running
     assert_that(calling(f2.result), raises(CancelledError))
diff --git a/tests/types/test_typehints.py b/tests/types/test_typehints.py
index e93c205..2c09a5a 100644
--- a/tests/types/test_typehints.py
+++ b/tests/types/test_typehints.py
@@ -4,7 +4,6 @@
 
 import pytest
 
-
 THIS_DIR = os.path.dirname(__file__)
 EXAMPLES = os.path.join(THIS_DIR, "type-examples")
 
@@ -20,7 +19,7 @@
 
     import mypy.api
 
-    (out, err, code) = mypy.api.run(
+    out, err, code = mypy.api.run(
         ["--disallow-any-expr", "--follow-imports", "skip", path]
     )