We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Release 'api_core-1.6.0a2'? or 'api_core-1.5.1'?
I'd like to use the changes from https://github.com/googleapis/google-cloud-python/pull/6310 in the library I'm working on.

Not sure about the version number for that one, since:

- I don't know what else has been released since 1.6.0a1
- I don't know what is intended by 1.6.0a1 in https://github.com/googleapis/google-cloud-python/pull/6267 (is it a pre-release?)

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `api_core/setup.py`
Content:
```
1 # Copyright 2018 Google LLC
2 #
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at
6 #
7 #     http://www.apache.org/licenses/LICENSE-2.0
8 #
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
14 
15 import io
16 import os
17 
18 import setuptools
19 
20 
21 # Package metadata.
22 
23 name = 'google-api-core'
24 description = 'Google API client core library'
25 version = '1.6.0a1'
26 # Should be one of:
27 # 'Development Status :: 3 - Alpha'
28 # 'Development Status :: 4 - Beta'
29 # 'Development Status :: 5 - Production/Stable'
30 release_status = 'Development Status :: 5 - Production/Stable'
31 dependencies = [
32     'googleapis-common-protos<2.0dev,>=1.5.3',
33     'protobuf>=3.4.0',
34     'google-auth<2.0.0dev,>=0.4.0',
35     'requests<3.0.0dev,>=2.18.0',
36     'setuptools>=34.0.0',
37     'six>=1.10.0',
38     'pytz',
39     'futures>=3.2.0;python_version<"3.2"'
40 ]
41 extras = {
42     'grpc': 'grpcio>=1.8.2',
43     'grpcio-gcp': 'grpcio-gcp>=0.2.2'
44 }
45 
46 
47 # Setup boilerplate below this line.
48 
49 package_root = os.path.abspath(os.path.dirname(__file__))
50 
51 readme_filename = os.path.join(package_root, 'README.rst')
52 with io.open(readme_filename, encoding='utf-8') as readme_file:
53     readme = readme_file.read()
54 
55 # Only include packages under the 'google' namespace. Do not include tests,
56 # benchmarks, etc.
57 packages = [
58     package for package in setuptools.find_packages()
59     if package.startswith('google')]
60 
61 # Determine which namespaces are needed.
62 namespaces = ['google']
63 if 'google.cloud' in packages:
64     namespaces.append('google.cloud')
65 
66 
67 setuptools.setup(
68     name=name,
69     version=version,
70     description=description,
71     long_description=readme,
72     author='Google LLC',
73     author_email='googleapis-packages@google.com',
74     license='Apache 2.0',
75     url='https://github.com/GoogleCloudPlatform/google-cloud-python',
76     classifiers=[
77         release_status,
78         'Intended Audience :: Developers',
79         'License :: OSI Approved :: Apache Software License',
80         'Programming Language :: Python',
81         'Programming Language :: Python :: 2',
82         'Programming Language :: Python :: 2.7',
83         'Programming Language :: Python :: 3',
84         'Programming Language :: Python :: 3.5',
85         'Programming Language :: Python :: 3.6',
86         'Programming Language :: Python :: 3.7',
87         'Operating System :: OS Independent',
88         'Topic :: Internet',
89     ],
90     platforms='Posix; MacOS X; Windows',
91     packages=packages,
92     namespace_packages=namespaces,
93     install_requires=dependencies,
94     extras_require=extras,
95     include_package_data=True,
96     zip_safe=False,
97 )
98
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/api_core/setup.py b/api_core/setup.py
--- a/api_core/setup.py
+++ b/api_core/setup.py
@@ -22,7 +22,7 @@
 
 name = 'google-api-core'
 description = 'Google API client core library'
-version = '1.6.0a1'
+version = '1.5.1'
 # Should be one of:
 # 'Development Status :: 3 - Alpha'
 # 'Development Status :: 4 - Beta'

{"golden_diff": "diff --git a/api_core/setup.py b/api_core/setup.py\n--- a/api_core/setup.py\n+++ b/api_core/setup.py\n@@ -22,7 +22,7 @@\n \n name = 'google-api-core'\n description = 'Google API client core library'\n-version = '1.6.0a1'\n+version = '1.5.1'\n # Should be one of:\n # 'Development Status :: 3 - Alpha'\n # 'Development Status :: 4 - Beta'\n", "issue": "Release 'api_core-1.6.0a2'? or 'api_core-1.5.1'?\nI'd like to use the changes from https://github.com/googleapis/google-cloud-python/pull/6310 in the library I'm working on.\r\n\r\nNot sure about the version number for that one, since:\r\n\r\n- I don't know what else has been released since 1.6.0a1\r\n- I don't know what is intended by 1.6.0a1 in https://github.com/googleapis/google-cloud-python/pull/6267 (is it a pre-release?)\n", "before_files": [{"content": "# Copyright 2018 Google LLC\n#\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#     http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nimport io\nimport os\n\nimport setuptools\n\n\n# Package metadata.\n\nname = 'google-api-core'\ndescription = 'Google API client core library'\nversion = '1.6.0a1'\n# Should be one of:\n# 'Development Status :: 3 - Alpha'\n# 'Development Status :: 4 - Beta'\n# 'Development Status :: 5 - Production/Stable'\nrelease_status = 'Development Status :: 5 - Production/Stable'\ndependencies = [\n    'googleapis-common-protos<2.0dev,>=1.5.3',\n    'protobuf>=3.4.0',\n    'google-auth<2.0.0dev,>=0.4.0',\n    'requests<3.0.0dev,>=2.18.0',\n    'setuptools>=34.0.0',\n    'six>=1.10.0',\n    'pytz',\n    'futures>=3.2.0;python_version<\"3.2\"'\n]\nextras = {\n    'grpc': 'grpcio>=1.8.2',\n    'grpcio-gcp': 'grpcio-gcp>=0.2.2'\n}\n\n\n# Setup boilerplate below this line.\n\npackage_root = os.path.abspath(os.path.dirname(__file__))\n\nreadme_filename = os.path.join(package_root, 'README.rst')\nwith io.open(readme_filename, encoding='utf-8') as readme_file:\n    readme = readme_file.read()\n\n# Only include packages under the 'google' namespace. Do not include tests,\n# benchmarks, etc.\npackages = [\n    package for package in setuptools.find_packages()\n    if package.startswith('google')]\n\n# Determine which namespaces are needed.\nnamespaces = ['google']\nif 'google.cloud' in packages:\n    namespaces.append('google.cloud')\n\n\nsetuptools.setup(\n    name=name,\n    version=version,\n    description=description,\n    long_description=readme,\n    author='Google LLC',\n    author_email='googleapis-packages@google.com',\n    license='Apache 2.0',\n    url='https://github.com/GoogleCloudPlatform/google-cloud-python',\n    classifiers=[\n        release_status,\n        'Intended Audience :: Developers',\n        'License :: OSI Approved :: Apache Software License',\n        'Programming Language :: Python',\n        'Programming Language :: Python :: 2',\n        'Programming Language :: Python :: 2.7',\n        'Programming Language :: Python :: 3',\n        'Programming Language :: Python :: 3.5',\n        'Programming Language :: Python :: 3.6',\n        'Programming Language :: Python :: 3.7',\n        'Operating System :: OS Independent',\n        'Topic :: Internet',\n    ],\n    platforms='Posix; MacOS X; Windows',\n    packages=packages,\n    namespace_packages=namespaces,\n    install_requires=dependencies,\n    extras_require=extras,\n    include_package_data=True,\n    zip_safe=False,\n)\n", "path": "api_core/setup.py"}], "after_files": [{"content": "# Copyright 2018 Google LLC\n#\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#     http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nimport io\nimport os\n\nimport setuptools\n\n\n# Package metadata.\n\nname = 'google-api-core'\ndescription = 'Google API client core library'\nversion = '1.5.1'\n# Should be one of:\n# 'Development Status :: 3 - Alpha'\n# 'Development Status :: 4 - Beta'\n# 'Development Status :: 5 - Production/Stable'\nrelease_status = 'Development Status :: 5 - Production/Stable'\ndependencies = [\n    'googleapis-common-protos<2.0dev,>=1.5.3',\n    'protobuf>=3.4.0',\n    'google-auth<2.0.0dev,>=0.4.0',\n    'requests<3.0.0dev,>=2.18.0',\n    'setuptools>=34.0.0',\n    'six>=1.10.0',\n    'pytz',\n    'futures>=3.2.0;python_version<\"3.2\"'\n]\nextras = {\n    'grpc': 'grpcio>=1.8.2',\n    'grpcio-gcp': 'grpcio-gcp>=0.2.2'\n}\n\n\n# Setup boilerplate below this line.\n\npackage_root = os.path.abspath(os.path.dirname(__file__))\n\nreadme_filename = os.path.join(package_root, 'README.rst')\nwith io.open(readme_filename, encoding='utf-8') as readme_file:\n    readme = readme_file.read()\n\n# Only include packages under the 'google' namespace. Do not include tests,\n# benchmarks, etc.\npackages = [\n    package for package in setuptools.find_packages()\n    if package.startswith('google')]\n\n# Determine which namespaces are needed.\nnamespaces = ['google']\nif 'google.cloud' in packages:\n    namespaces.append('google.cloud')\n\n\nsetuptools.setup(\n    name=name,\n    version=version,\n    description=description,\n    long_description=readme,\n    author='Google LLC',\n    author_email='googleapis-packages@google.com',\n    license='Apache 2.0',\n    url='https://github.com/GoogleCloudPlatform/google-cloud-python',\n    classifiers=[\n        release_status,\n        'Intended Audience :: Developers',\n        'License :: OSI Approved :: Apache Software License',\n        'Programming Language :: Python',\n        'Programming Language :: Python :: 2',\n        'Programming Language :: Python :: 2.7',\n        'Programming Language :: Python :: 3',\n        'Programming Language :: Python :: 3.5',\n        'Programming Language :: Python :: 3.6',\n        'Programming Language :: Python :: 3.7',\n        'Operating System :: OS Independent',\n        'Topic :: Internet',\n    ],\n    platforms='Posix; MacOS X; Windows',\n    packages=packages,\n    namespace_packages=namespaces,\n    install_requires=dependencies,\n    extras_require=extras,\n    include_package_data=True,\n    zip_safe=False,\n)\n", "path": "api_core/setup.py"}]}