}

    /**
     * Get active resource information
     *
     * @return set of active resource descriptions
     */
    public Set<String> getActiveResources() {
        Set<String> result = Collections.newSetFromMap(new ConcurrentHashMap<>());

        for (ResourceHolder holder : activeResources.values()) {
            if (!holder.closed && holder.isAlive()) {

    void testGetActiveResources() {
        TestResource resource = new TestResource("active1");
        resourceManager.registerResource(resource);

        var activeResources = resourceManager.getActiveResources();
        assertNotNull(activeResources);
        assertFalse(activeResources.isEmpty());

        boolean found = activeResources.stream().anyMatch(desc -> desc.contains("TestResource"));