public List<String> findAvailableSecret(String appId) {
    return accessKeyServiceWithCache.getAvailableSecrets(appId);
  }
@Test
  public void testFindAvailableSecret() {
    String appId = "someAppId";
    List<String> returnSecrets = Lists.newArrayList("someSecret");

    when(accessKeyServiceWithCache.getAvailableSecrets(appId)).thenReturn(returnSecrets);

    List<String> availableSecret = accessKeyUtil.findAvailableSecret(appId);

    assertThat(availableSecret).containsExactly("someSecret");
    verify(accessKeyServiceWithCache).getAvailableSecrets(appId);
  }