// This is to prevent the jar file being held open
        URL url = new URL("jar:file://valid_jar_url_syntax.jar!/")
        URLConnection urlConnection = url.openConnection()
        def original = urlConnection.getDefaultUseCaches()
        urlConnection.setDefaultUseCaches(false)

        try {
            URL[] urls = [new URL("jar:${jar.toURI().toURL()}!/")] as URL[]
            URLClassLoader ucl = new URLClassLoader(urls)

        this.ifModifiedSince = ifModifiedSince;
    }

    public long getIfModifiedSince() {
        return connection.getIfModifiedSince();
    }

    public boolean getDefaultUseCaches() {
        return connection.getDefaultUseCaches();
    }

    public void setDefaultUseCaches(boolean defaultUseCaches) {
        connection.setDefaultUseCaches(defaultUseCaches);
    }

    }


    @Override
    public long getIfModifiedSince () {
        return this.connection.getIfModifiedSince();
    }


    @Override
    public boolean getDefaultUseCaches () {
        return this.connection.getDefaultUseCaches();
    }


    @Override
    public void setDefaultUseCaches ( boolean defaultUseCaches ) {
        this.connection.setDefaultUseCaches(defaultUseCaches);
    }