String seed = "test_seed";
        String[] tags = null;
        String[] roles = null;
        String[] fields = null;
        String[] excludes = null;

        String result = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);

        assertNotNull(result);
        assertTrue(result.contains("test_seed"));

import org.junit.Test;

/**
 * @author shinsuke
 *
 */
public class ThreadUtilTest {

    /**
     * @throws Exception
     */
    @Test
    public void test_sleep() throws Exception {
        ThreadUtil.sleep(1L);
        assertTrue(true);
        ThreadUtil.sleepQuietly(1L);
    }

    /**
     * @throws Exception
     */
    @Test