def METHOD_NAME(self, url, verifier=None, **kwargs):
    """Method for fetching an access token from the token endpoint.
    This is the final step in the OAuth 1 workflow. An access token is
    obtained using all previously obtained credentials, including the
    verifier from the authorization step.
    :param url: Access Token endpoint.
    :param verifier: A verifier string to prove authorization was granted.
    :param kwargs: Extra parameters to include for fetching access token.
    :return: A token dict.
    """
    if verifier:
        self.auth.verifier = verifier
    if not self.auth.verifier:
        self.handle_error('missing_verifier', 'Missing "verifier" value')
    return self._fetch_token(url, **kwargs)