* @return best available RDMA provider, or null if none available
     */
    public static RdmaProvider createProvider(String preference) {
        if ("auto".equalsIgnoreCase(preference)) {
            return selectBestProvider();
        }

        switch (preference.toLowerCase()) {
        case "disni":
            RdmaProvider disniProvider = new DisniRdmaProvider();
            if (disniProvider.isAvailable()) {

        assertNull(provider, "Unknown provider should return null");
    }

    @Test
    public void testSelectBestProvider() {
        RdmaProvider provider = RdmaProviderFactory.selectBestProvider();
        assertNotNull(provider, "Should always return at least TCP provider");
        assertTrue(provider.isAvailable(), "Selected provider should be available");
    }

    @Test