diff -upr google-api-core-2.7.2.orig/tests/asyncio/future/test_async_future.py google-api-core-2.7.2/tests/asyncio/future/test_async_future.py
--- google-api-core-2.7.2.orig/tests/asyncio/future/test_async_future.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/future/test_async_future.py	2022-05-12 11:14:18.402281504 +0200
@@ -14,7 +14,7 @@
 
 import asyncio
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import exceptions
diff -upr google-api-core-2.7.2.orig/tests/asyncio/gapic/test_method_async.py google-api-core-2.7.2/tests/asyncio/gapic/test_method_async.py
--- google-api-core-2.7.2.orig/tests/asyncio/gapic/test_method_async.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/gapic/test_method_async.py	2022-05-12 11:14:18.402281504 +0200
@@ -14,7 +14,7 @@
 
 import datetime
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/asyncio/operations_v1/test_operations_async_client.py google-api-core-2.7.2/tests/asyncio/operations_v1/test_operations_async_client.py
--- google-api-core-2.7.2.orig/tests/asyncio/operations_v1/test_operations_async_client.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/operations_v1/test_operations_async_client.py	2022-05-12 11:14:18.402281504 +0200
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/asyncio/test_grpc_helpers_async.py google-api-core-2.7.2/tests/asyncio/test_grpc_helpers_async.py
--- google-api-core-2.7.2.orig/tests/asyncio/test_grpc_helpers_async.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/test_grpc_helpers_async.py	2022-05-12 11:14:18.402281504 +0200
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 import pytest  # noqa: I202
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/asyncio/test_operation_async.py google-api-core-2.7.2/tests/asyncio/test_operation_async.py
--- google-api-core-2.7.2.orig/tests/asyncio/test_operation_async.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/test_operation_async.py	2022-05-12 11:14:18.402281504 +0200
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/asyncio/test_page_iterator_async.py google-api-core-2.7.2/tests/asyncio/test_page_iterator_async.py
--- google-api-core-2.7.2.orig/tests/asyncio/test_page_iterator_async.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/test_page_iterator_async.py	2022-05-12 11:14:18.402281504 +0200
@@ -14,7 +14,7 @@
 
 import inspect
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import page_iterator_async
@@ -126,7 +126,7 @@ class TestAsyncIterator:
         item2 = 100
         item3 = 211
 
-        # Make pages from mock responses
+        # Make pages from unittest.mock responses
         parent = mock.sentinel.parent
         page1 = page_iterator_async.Page(
             parent, (item1, item2), page_iterator_async._item_to_value_identity
diff -upr google-api-core-2.7.2.orig/tests/asyncio/test_retry_async.py google-api-core-2.7.2/tests/asyncio/test_retry_async.py
--- google-api-core-2.7.2.orig/tests/asyncio/test_retry_async.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/asyncio/test_retry_async.py	2022-05-12 11:14:18.402281504 +0200
@@ -15,7 +15,7 @@
 import datetime
 import re
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import exceptions
diff -upr google-api-core-2.7.2.orig/tests/unit/future/test__helpers.py google-api-core-2.7.2/tests/unit/future/test__helpers.py
--- google-api-core-2.7.2.orig/tests/unit/future/test__helpers.py	2022-05-12 11:14:18.390281427 +0200
+++ google-api-core-2.7.2/tests/unit/future/test__helpers.py	2022-05-12 11:14:18.402281504 +0200
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 
 from google.api_core.future import _helpers
 
diff -upr google-api-core-2.7.2.orig/tests/unit/future/test_polling.py google-api-core-2.7.2/tests/unit/future/test_polling.py
--- google-api-core-2.7.2.orig/tests/unit/future/test_polling.py	2022-05-12 11:14:18.390281427 +0200
+++ google-api-core-2.7.2/tests/unit/future/test_polling.py	2022-05-12 11:14:18.402281504 +0200
@@ -16,7 +16,7 @@ import concurrent.futures
 import threading
 import time
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import exceptions, retry
diff -upr google-api-core-2.7.2.orig/tests/unit/gapic/test_method.py google-api-core-2.7.2/tests/unit/gapic/test_method.py
--- google-api-core-2.7.2.orig/tests/unit/gapic/test_method.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/gapic/test_method.py	2022-05-12 11:14:18.402281504 +0200
@@ -14,7 +14,7 @@
 
 import datetime
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/unit/operations_v1/test_operations_rest_client.py google-api-core-2.7.2/tests/unit/operations_v1/test_operations_rest_client.py
--- google-api-core-2.7.2.orig/tests/unit/operations_v1/test_operations_rest_client.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/operations_v1/test_operations_rest_client.py	2022-05-12 11:14:18.402281504 +0200
@@ -15,7 +15,7 @@
 #
 import os
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/unit/test_bidi.py google-api-core-2.7.2/tests/unit/test_bidi.py
--- google-api-core-2.7.2.orig/tests/unit/test_bidi.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_bidi.py	2022-05-12 11:14:18.402281504 +0200
@@ -17,7 +17,7 @@ import logging
 import queue
 import threading
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/unit/test_exceptions.py google-api-core-2.7.2/tests/unit/test_exceptions.py
--- google-api-core-2.7.2.orig/tests/unit/test_exceptions.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_exceptions.py	2022-05-12 11:14:18.402281504 +0200
@@ -15,7 +15,7 @@
 import http.client
 import json
 
-import mock
+from unittest import mock
 import pytest
 import requests
 
diff -upr google-api-core-2.7.2.orig/tests/unit/test_extended_operation.py google-api-core-2.7.2/tests/unit/test_extended_operation.py
--- google-api-core-2.7.2.orig/tests/unit/test_extended_operation.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_extended_operation.py	2022-05-12 11:14:18.402281504 +0200
@@ -16,7 +16,7 @@ import dataclasses
 import enum
 import typing
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import exceptions
diff -upr google-api-core-2.7.2.orig/tests/unit/test_grpc_helpers.py google-api-core-2.7.2/tests/unit/test_grpc_helpers.py
--- google-api-core-2.7.2.orig/tests/unit/test_grpc_helpers.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_grpc_helpers.py	2022-05-12 11:14:18.402281504 +0200
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/unit/test_operation.py google-api-core-2.7.2/tests/unit/test_operation.py
--- google-api-core-2.7.2.orig/tests/unit/test_operation.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_operation.py	2022-05-12 11:14:18.406281529 +0200
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 
-import mock
+from unittest import mock
 import pytest
 
 try:
diff -upr google-api-core-2.7.2.orig/tests/unit/test_page_iterator.py google-api-core-2.7.2/tests/unit/test_page_iterator.py
--- google-api-core-2.7.2.orig/tests/unit/test_page_iterator.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_page_iterator.py	2022-05-12 11:14:18.406281529 +0200
@@ -15,7 +15,7 @@
 import math
 import types
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import page_iterator
@@ -177,7 +177,7 @@ class TestIterator(object):
         item2 = 100
         item3 = 211
 
-        # Make pages from mock responses
+        # Make pages from unittest.mock responses
         parent = mock.sentinel.parent
         page1 = page_iterator.Page(
             parent, (item1, item2), page_iterator._item_to_value_identity
diff -upr google-api-core-2.7.2.orig/tests/unit/test_path_template.py google-api-core-2.7.2/tests/unit/test_path_template.py
--- google-api-core-2.7.2.orig/tests/unit/test_path_template.py	2022-05-12 11:14:18.386281401 +0200
+++ google-api-core-2.7.2/tests/unit/test_path_template.py	2022-05-12 11:14:18.406281529 +0200
@@ -14,7 +14,7 @@
 
 from __future__ import unicode_literals
 
-import mock
+from unittest import mock
 import pytest
 
 from google.api_core import path_template
diff -upr google-api-core-2.7.2.orig/tests/unit/test_retry.py google-api-core-2.7.2/tests/unit/test_retry.py
--- google-api-core-2.7.2.orig/tests/unit/test_retry.py	2022-05-12 11:14:18.390281427 +0200
+++ google-api-core-2.7.2/tests/unit/test_retry.py	2022-05-12 11:14:18.406281529 +0200
@@ -16,7 +16,7 @@ import datetime
 import itertools
 import re
 
-import mock
+from unittest import mock
 import pytest
 import requests.exceptions
 
diff -upr google-api-core-2.7.2.orig/tests/unit/test_timeout.py google-api-core-2.7.2/tests/unit/test_timeout.py
--- google-api-core-2.7.2.orig/tests/unit/test_timeout.py	2022-05-12 11:14:18.390281427 +0200
+++ google-api-core-2.7.2/tests/unit/test_timeout.py	2022-05-12 11:14:18.406281529 +0200
@@ -15,7 +15,7 @@
 import datetime
 import itertools
 
-import mock
+from unittest import mock
 
 from google.api_core import timeout