70 def _initialize_headers(headers):  argument
71     """Creates a copy of the headers.
74         headers: dict, request headers to copy.
77         dict, the copied headers or a new dictionary if the headers
80     return {} if headers is None else dict(headers)
83 def _apply_user_agent(headers, user_agent):  argument
84     """Adds a user-agent to the headers.
87         headers: dict, request headers to add / modify user
92         dict, the original headers passed in, but modified if the
96         if 'user-agent' in headers:
97             headers['user-agent'] = (user_agent + ' ' + headers['user-agent'])
99             headers['user-agent'] = user_agent
101     return headers
104 def clean_headers(headers):  argument
112         headers: dict, A dictionary of headers.
119         for k, v in six.iteritems(headers):
147     def new_request(uri, method='GET', body=None, headers=None,  argument
155         # Clone and modify the request headers to add the appropriate
157         headers = _initialize_headers(headers)
158         credentials.apply(headers)
159         _apply_user_agent(headers, credentials.user_agent)
168                                             clean_headers(headers),
181             credentials.apply(headers)
186                                                 clean_headers(headers),
217     def new_request(uri, method='GET', body=None, headers=None,  argument
226                                                 headers, redirections,
231             headers = _initialize_headers(headers)
232             _apply_user_agent(headers, credentials.user_agent)
236             headers['Authorization'] = 'Bearer ' + token
238                                        clean_headers(headers),