'Add token to the request uri, body or authorization header.
The access token type provides the client with the information
required to successfully utilize the access token to make a protected
resource request (along with type-specific attributes).  The client
MUST NOT use an access token if it does not understand the token
type.
For example, the "bearer" token type defined in
[I-D.ietf-oauth-v2-bearer] is utilized by simply including the access
token string in the request:
GET /resource/1 HTTP/1.1
Host: example.com
Authorization: Bearer mF_9.B5f-4.1JqM
while the "mac" token type defined in [I-D.ietf-oauth-v2-http-mac] is
utilized by issuing a MAC key together with the access token which is
used to sign certain components of the HTTP requests:
GET /resource/1 HTTP/1.1
Host: example.com
Authorization: MAC id="h480djs93hd8",
nonce="274312:dj83hs9s",
mac="kDZvddkndxvhGRXZhvuDjEWhGeE="
.. _`I-D.ietf-oauth-v2-bearer`: http://tools.ietf.org/html/draft-ietf-oauth-v2-28#ref-I-D.ietf-oauth-v2-bearer
.. _`I-D.ietf-oauth-v2-http-mac`: http://tools.ietf.org/html/draft-ietf-oauth-v2-28#ref-I-D.ietf-oauth-v2-http-mac'

def add_token(self, uri, http_method=u'GET', body=None, headers=None, token_placement=AUTH_HEADER):

    return self.token_types[self.token_type](uri, http_method, body, headers, token_placement)
