def get_authentication_tokens(self, callback_url=None, force_login=False,<EOL>screen_name='<STR_LIT>'):
if self.oauth_version != <NUM_LIT:1>:<EOL><INDENT>raise TwythonError('<STR_LIT>')<EOL><DEDENT>request_args = {}<EOL>if callback_url:<EOL><INDENT>request_args['<STR_LIT>'] = callback_url<EOL><DEDENT>response = self.client.get(self.request_token_url, params=request_args)<EOL>if response.status_code == <NUM_LIT>:<EOL><INDENT>raise TwythonAuthError(response.content,<EOL>error_code=response.status_code)<EOL><DEDENT>elif response.status_code != <NUM_LIT:200>:<EOL><INDENT>raise TwythonError(response.content,<EOL>error_code=response.status_code)<EOL><DEDENT>request_tokens = dict(parse_qsl(response.content.decode('<STR_LIT:utf-8>')))<EOL>if not request_tokens:<EOL><INDENT>raise TwythonError('<STR_LIT>')<EOL><DEDENT>oauth_callback_confirmed = request_tokens.get('<STR_LIT>')== '<STR_LIT:true>'<EOL>auth_url_params = {<EOL>'<STR_LIT>': request_tokens['<STR_LIT>'],<EOL>}<EOL>if force_login:<EOL><INDENT>auth_url_params.update({<EOL>'<STR_LIT>': force_login,<EOL>'<STR_LIT>': screen_name<EOL>})<EOL><DEDENT>if callback_url and not oauth_callback_confirmed:<EOL><INDENT>auth_url_params['<STR_LIT>'] = self.callback_url<EOL><DEDENT>request_tokens['<STR_LIT>'] = self.authenticate_url +'<STR_LIT:?>' + urlencode(auth_url_params)<EOL>return request_tokens<EOL>
Returns a dict including an authorization URL, ``auth_url``, to
           direct a user to

        :param callback_url: (optional) Url the user is returned to after
                             they authorize your app (web clients only)
        :param force_login: (optional) Forces the user to enter their
                            credentials to ensure the correct users
                            account is authorized.
        :param screen_name: (optional) If forced_login is set OR user is
                            not currently logged in, Prefills the username
                            input box of the OAuth login screen with the
                            given value

        :rtype: dict