Appease black.

Author: ab

requests_oauthlib/oauth2_session.py

@@ -555,24 +555,24 @@ def _raise_for_5xx(self, response):
         :param response: HTTP response object from requests
         Raises :class:`requests.exceptions.HTTPError`, if a 5XX error occurred.
         """
-        http_error_msg = ''
+        http_error_msg = ""
         if isinstance(response.reason, bytes):
             # We attempt to decode utf-8 first because some servers
             # choose to localize their reason strings. If the string
             # isn't utf-8, we fall back to iso-8859-1 for all other
             # encodings. (See psf/requests PR #3538)
             try:
-                reason = response.reason.decode('utf-8')
+                reason = response.reason.decode("utf-8")
             except UnicodeDecodeError:
-                reason = response.reason.decode('iso-8859-1')
+                reason = response.reason.decode("iso-8859-1")
         else:
             reason = response.reason
 
         if 400 <= response.status_code < 500:
             pass  # ignored
 
         elif 500 <= response.status_code < 600:
-            http_error_msg = u'%s Server Error: %s for url: %s' % (
+            http_error_msg = "%s Server Error: %s for url: %s" % (
                 response.status_code, reason, response.url
             )