Requests: リクエスト2.11：整数値のヘッダーでcheck_header_validityが失敗しました

やあ、

リクエスト2.11以降、アプリのリクエストを使用したすべての通話が中断されます。 デバッグ後、このバージョンは以前のように整数値のヘッダーを受け入れないようです。

2.10：

In [1]: import requests

In [2]: requests.get('http://bing.com', headers={'Content-Length': 42})
Out[2]: <Response [200]>

2.11

In [1]: import requests

In [2]: requests.get('http://bing.com', headers={'Content-Length': 42})
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\utils.py in check_header_validity(header)
    751     try:
--> 752         if not pat.match(value):
    753             raise InvalidHeader("Invalid return character or leading space in header: %s" % name)

TypeError: expected string or bytes-like object

During handling of the above exception, another exception occurred:

InvalidHeader                             Traceback (most recent call last)
<ipython-input-2-ae7ec2933e34> in <module>()
----> 1 requests.get('http://bing.com', headers={'Content-Length': 42})

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\api.py in get(url, params, **kwargs)
     68
     69     kwargs.setdefault('allow_redirects', True)
---> 70     return request('get', url, params=params, **kwargs)
     71
     72

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\api.py in request(method, url, **kwargs)
     54     # cases, and look like a memory leak in others.
     55     with sessions.Session() as session:
---> 56         return session.request(method=method, url=url, **kwargs)
     57
     58

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\sessions.py in request(self, method, url, params, data, headers, cookies, files, auth, timeout, allow_redirects, proxies, hooks, stream, verify, cert, json)
    455             hooks = hooks,
    456         )
--> 457         prep = self.prepare_request(req)
    458
    459         proxies = proxies or {}

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\sessions.py in prepare_request(self, request)
    388             auth=merge_setting(auth, self.auth),
    389             cookies=merged_cookies,
--> 390             hooks=merge_hooks(request.hooks, self.hooks),
    391         )
    392         return p

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\models.py in prepare(self, method, url, headers, files, data, params, auth, cookies, hooks, json)
    293         self.prepare_method(method)
    294         self.prepare_url(url, params)
--> 295         self.prepare_headers(headers)
    296         self.prepare_cookies(cookies)
    297         self.prepare_body(data, files, json)

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\models.py in prepare_headers(self, headers)
    407             for header in headers.items():
    408                 # Raise exception on invalid header value.
--> 409                 check_header_validity(header)
    410                 name, value = header
    411                 self.headers[to_native_string(name)] = value

D:\VSProjects\azure-sdk-for-python\env3.5\Lib\site-packages\requests\utils.py in check_header_validity(header)
    754     except TypeError:
    755         raise InvalidHeader("Header value %s must be of type str or bytes, "
--> 756                             "not %s" % (value, type(value)))
    757
    758

InvalidHeader: Header value 42 must be of type str or bytes, not <class 'int'>

各リクエストで「Content-Length」を定義します。 とにかく、意味的に整数であるヘッダーに整数を使用することは意味がありませんか？