def METHOD_NAME(self):
    """If the access token request is valid and authorized, the
    authorization server issues an access token and optional refresh
    token.
    """
    client = self.request.client
    scope = self.request.credential.get_scope()
    token = self.generate_token(
        user=self.request.user,
        scope=scope,
        include_refresh_token=client.check_grant_type('refresh_token'),
    )
    log.debug('Issue token %r to %r', token, client)
    self.save_token(token)
    self.execute_hook('process_token', token=token)
    return 200, token, self.TOKEN_RESPONSE_HEADER