Pygithub: Al objeto de rama le faltan la mayoría de los atributos y métodos

Estoy jugando con esta biblioteca con la esperanza de poder automatizar las cosas en nuestro Github Enterprise. Una de las primeras cosas que debo hacer es establecer protecciones de rama para nuestros repositorios. Sin embargo, cuando inicio un objeto Branch desde un repositorio de prueba (que ya tenía configuradas las protecciones de rama, fíjate), el único atributo que ha asignado es "nombre", y la mayoría de los métodos enumerados en la documentación no existen en el objeto:

import github
github.enable_console_debug_logging()
Github = github.Github

Github("myuser",
'mycreds',
base_url="https://ghe.workworkwork.com/api/v3")

master = g.get_user("myuser").get_repo('cookbook1').get_branch('master')
print master
print master.protection_url

La salida:

...
GET https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/branches/master {'Authorization': 'Basic (login and password removed)', 'User-Agent': 'PyGithub/Python'} None ==> 200 {'status': '200 OK', 'content-length': '2925', 'x-github-media-type': 'github.v3', 'x-content-type-options': 'nosniff', 'content-security-policy': "default-src 'none'", 'access-control-expose-headers': 'ETag, Link, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval', 'x-github-request-id': '0ec6f4e8-2355-41dc-859d-0e7076a294b1', 'strict-transport-security': 'max-age=31536000; includeSubdomains', 'vary': 'Accept, Authorization, Cookie, X-GitHub-OTP', 'server': 'GitHub.com', 'access-control-allow-origin': '*', 'etag': '"965449c848ed3319d7e028c2a587f414"', 'x-xss-protection': '1; mode=block', 'cache-control': 'private, max-age=60, s-maxage=60', 'date': 'Thu, 16 Aug 2018 23:41:19 GMT', 'x-frame-options': 'deny', 'x-oauth-scopes': 'admin:org_hook, admin:pre_receive_hook, admin:repo_hook, repo', 'content-type': 'application/json; charset=utf-8', 'x-accepted-oauth-scopes': ''} {"name":"master","commit":{"sha":"3548233b67c8ec4cad703ff947fa0ba022df7c66","commit":{"author":{"name":"Garrett Anderson","email":"[email protected]","date":"2018-08-16T18:44:44Z"},"committer":{"name":"GitHub Enterprise","email":"[email protected]","date":"2018-08-16T18:44:44Z"},"message":"Merge pull request #8 from myuser/newfork\n\nwhat","tree":{"sha":"44b3a300094b2ccbbfb79ea7df5f82e627c12b42","url":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/git/trees/44b3a300094b2ccbbfb79ea7df5f82e627c12b42"},"url":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/git/commits/3548233b67c8ec4cad703ff947fa0ba022df7c66","comment_count":0},"url":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/commits/3548233b67c8ec4cad703ff947fa0ba022df7c66","html_url":"https://ghe.workworkwork.com/myuser/cookbook1/commit/3548233b67c8ec4cad703ff947fa0ba022df7c66","comments_url":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/commits/3548233b67c8ec4cad703ff947fa0ba022df7c66/comments","author":{"login":"myuser","id":593,"avatar_url":"https://ghe.workworkwork.com/avatars/u/593?","gravatar_id":"","url":"https://ghe.workworkwork.com/api/v3/users/myuser","html_url":"https://ghe.workworkwork.com/myuser","followers_url":"https://ghe.workworkwork.com/api/v3/users/myuser/followers","following_url":"https://ghe.workworkwork.com/api/v3/users/myuser/following{/other_user}","gists_url":"https://ghe.workworkwork.com/api/v3/users/myuser/gists{/gist_id}","starred_url":"https://ghe.workworkwork.com/api/v3/users/myuser/starred{/owner}{/repo}","subscriptions_url":"https://ghe.workworkwork.com/api/v3/users/myuser/subscriptions","organizations_url":"https://ghe.workworkwork.com/api/v3/users/myuser/orgs","repos_url":"https://ghe.workworkwork.com/api/v3/users/myuser/repos","events_url":"https://ghe.workworkwork.com/api/v3/users/myuser/events{/privacy}","received_events_url":"https://ghe.workworkwork.com/api/v3/users/myuser/received_events","type":"User","site_admin":true},"committer":null,"parents":[{"sha":"067642113fe45ee77160ee28cafc4870f2c06b6a","url":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/commits/067642113fe45ee77160ee28cafc4870f2c06b6a","html_url":"https://ghe.workworkwork.com/myuser/cookbook1/commit/067642113fe45ee77160ee28cafc4870f2c06b6a"},{"sha":"3a9479c605617a9035cd986a4bf77880ac5dde64","url":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/commits/3a9479c605617a9035cd986a4bf77880ac5dde64","html_url":"https://ghe.workworkwork.com/myuser/cookbook1/commit/3a9479c605617a9035cd986a4bf77880ac5dde64"}]},"_links":{"self":"https://ghe.workworkwork.com/api/v3/repos/myuser/cookbook1/branches/master","html":"https://ghe.workworkwork.com/myuser/cookbook1/tree/master"}}

Branch(name="master")

AttributeError: 'Branch' object has no attribute 'protection_url'

Tampoco hay ninguno de los métodos allí:

print master.get_required_status_checks()
OUTPUT:
AttributeError: 'Branch' object has no attribute 'get_required_status_checks'

O este atributo:

print master.protection
OUTPUT:
return self._protected.value
AttributeError: 'Branch' object has no attribute '_protected'

El objeto tiene este aspecto:

print dir(master)
OUTPUT:
['CHECK_AFTER_INIT_FLAG', '_GithubObject__makeSimpleAttribute', '_GithubObject__makeSimpleListAttribute', '_GithubObject__makeTransformedAttribute', '__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_commit', '_completeIfNeeded', '_headers', '_initAttributes', '_makeBoolAttribute', '_makeClassAttribute', '_makeDatetimeAttribute', '_makeDictAttribute', '_makeDictOfStringsToClassesAttribute', '_makeIntAttribute', '_makeListOfClassesAttribute', '_makeListOfIntsAttribute', '_makeListOfListOfStringsAttribute', '_makeListOfStringsAttribute', '_makeStringAttribute', '_makeTimestampAttribute', '_name', '_parentUrl', '_rawData', '_requester', '_storeAndUseAttributes', '_useAttributes', 'commit', 'contexts', 'enforcement_level', 'etag', 'get__repr__', 'last_modified', 'name', 'protected', 'raw_data', 'raw_headers', 'setCheckAfterInitFlag']

Parece que el objeto no se está creando correctamente.