def METHOD_NAME(self, username, password):
    self.log.info("Logging in as %s", username)
    url = "{}/login.php?do=login".format(self.root)
    data = {
        "vb_login_username": username,
        "vb_login_password": password,
        "do"               : "login",
        "cookieuser"       : "1",
    }
    response = self.request(url, method="POST", data=data)
    if not response.cookies.get("vg_password"):
        raise exception.AuthenticationError()
    return {cookie.name: cookie.value
            for cookie in response.cookies}