public static BadRequestException appNamespaceNotExists(String appId, String namespaceName) {
    return new BadRequestException("appNamespace not exist for appId:%s namespaceName:%s", appId, namespaceName);
  }
@Test
  public void testAppNamespaceNotExists() {
    BadRequestException appNamespaceNotExists = BadRequestException.appNamespaceNotExists(appId, namespaceName);
    assertEquals("appNamespace not exist for appId:app-1001 namespaceName:application", appNamespaceNotExists.getMessage());
  }