public static BadRequestException itemAlreadyExists(String itemKey) {
    return new BadRequestException("item already exists for itemKey:%s", itemKey);
  }
@Test
  public void testItemAlreadyExists() {
    BadRequestException itemAlreadyExists = BadRequestException.itemAlreadyExists("itemKey");
    assertEquals("item already exists for itemKey:itemKey", itemAlreadyExists.getMessage());
  }