NATURAL_ORDER.java

    public static final Ordering<SubCategory> NATURAL_ORDER;

    static
    {
        NATURAL_ORDER = new Ordering<SubCategory>() {
            @Override
            public int compare(@Nullable final SubCategory left, @Nullable final SubCategory right)
            {
                return ComparisonChain.start()
                .compare(checkNotNull(left).categoryId, checkNotNull(right).categoryId)
                .compare(left.subCategoryId, right.subCategoryId)
                .result();
            }
        };
    }