public String logout(final String postAuthRedirectUri) {
        final String endpoint = openIdConfiguration.getLogoutEndpoint();
        final String clientId = openIdConfiguration.getClientId();
        Objects.requireNonNull(endpoint,
                "To make a logout request the OpenId config 'logoutEndpoint' must not be null");
        Objects.requireNonNull(clientId,
                "To make an authentication request the OpenId config 'clientId' must not be null");
        final AuthenticationState state = authenticationStateCache.create(postAuthRedirectUri, true);
        LOGGER.debug(() -> "logout state=" + state);
        return createLogoutUri(endpoint, clientId, state);
    }
This method attempts to get a token from the request headers and, if present, use that to login.
stroom-security/stroom-security-impl/src/main/java/stroom/security/impl/OpenIdManager.java