@Override
    public String getLogoutEndpoint() {
        final String logoutEndpoint = delegate.getLogoutEndpoint();
        // If the IdP doesn't provide a logout endpoint then use the internal one to invalidate
        // the session and redirect to perform a new auth flow.

        return NullSafe.isBlankString(logoutEndpoint)
                ? uriFactory.publicUri(InternalIdpConfigurationProvider.INTERNAL_AUTH_ENDPOINT).toString()
                : logoutEndpoint;
    }
A front for the internal and external OIDC config providers. The useInternal prop in local
config controls which delegate is used.
stroom-security/stroom-security-impl/src/main/java/stroom/security/impl/DelegatingIdpConfigurationProvider.java