Enforce noninstantiability to UtilNumber class

    // ICU4J rule sets for the en_US locale. To add more rules, expand this string.
    // For reference, see the RbnfSampleRuleSets.java file distributed with ICU4J
    public static final String ruleSet_en_US =
        /*
         * These rules format a number in one of the two styles often used
         * on checks.  %dollars-and-hundredths formats cents as hundredths of
         * a dollar (23.40 comes out as "twenty-three and 40/100 dollars").
         * %dollars-and-cents formats in dollars and cents (23.40 comes out as
         * "twenty-three dollars and forty cents")
         */
        "%dollars-and-cents:\n"
        + "    x.0: << [and >%%cents>];\n"
        + "    0.x: >%%cents>;\n"
        + "    0: zero dollars; one dollar; =%%main= dollars;\n"
        + "%%main:\n"
        + "    zero; one; two; three; four; five; six; seven; eight; nine;\n"
        + "    ten; eleven; twelve; thirteen; fourteen; fifteen; sixteen;\n"
        + "        seventeen; eighteen; nineteen;\n"
        + "    20: twenty[->>];\n"
        + "    30: thirty[->>];\n"
        + "    40: forty[->>];\n"
        + "    50: fifty[->>];\n"
        + "    60: sixty[->>];\n"
        + "    70: seventy[->>];\n"
        + "    80: eighty[->>];\n"
        + "    90: ninety[->>];\n"
        + "    100: << hundred[ >>];\n"
        + "    1000: << thousand[ >>];\n"
        + "    1,000,000: << million[ >>];\n"
        + "    1,000,000,000: << billion[ >>];\n"
        + "    1,000,000,000,000: << trillion[ >>];\n"
        + "    1,000,000,000,000,000: =#,##0=;\n"
        + "%%cents:\n"
        + "    100: <%%main< cent[s];\n"
        + "%dollars-and-hundredths:\n"
        + "    x.0: <%%main< and >%%hundredths>/100;\n" // this used to end in 'dollars' but that should be added later
        + "%%hundredths:\n"
        + "    100: <00<;\n";

    // ICU4J rule sets for the th_TH locale. To add more rules, expand this string.
    // For reference, see the RbnfSampleRuleSets.java file distributed with ICU4J
    public static final String ruleSet_th_TH =
        /*
         * These rules format a number in one of the two styles often used
         * on checks.  %bahts-and-hundredths formats stangs as hundredths of
         * a baht (23.40 comes out as "twenty-three and 40/100 bahts").
         * %bahts-and-stangs formats in bahts and stangs (23.40 comes out as
         * "twenty-three bahts and forty stangs")
         */
        "%bahts-and-stangs:\n"
        + "    x.0: << [and >%%stangs>];\n"
        + "    0.x: >%%stangs>;\n"
        + "    0: zero bahts; one baht; =%%main= bahts;\n"
        + "%%main:\n"
        + "    zero; one; two; three; four; five; six; seven; eight; nine;\n"
        + "    ten; eleven; twelve; thirteen; fourteen; fifteen; sixteen;\n"
        + "        seventeen; eighteen; nineteen;\n"
        + "    20: twenty[->>];\n"
        + "    30: thirty[->>];\n"
        + "    40: forty[->>];\n"
        + "    50: fifty[->>];\n"
        + "    60: sixty[->>];\n"
        + "    70: seventy[->>];\n"
        + "    80: eighty[->>];\n"
        + "    90: ninety[->>];\n"
        + "    100: << hundred[ >>];\n"
        + "    1000: << thousand[ >>];\n"
        + "    1,000,000: << million[ >>];\n"
        + "    1,000,000,000: << billion[ >>];\n"
        + "    1,000,000,000,000: << trillion[ >>];\n"
        + "    1,000,000,000,000,000: =#,##0=;\n"
        + "%%stangs:\n"
        + "    100: <%%main< stang[s];\n"
        + "%bahts-and-hundredths:\n"
        + "    x.0: <%%main< and >%%hundredths>/100;\n" // this used to end in 'bahts' but that should be added later
        + "%%hundredths:\n"
        + "    100: <00<;\n";

    // hash map to store ICU4J rule sets keyed to Locale
    public static HashMap<Locale, String> rbnfRuleSets;
    static {
        rbnfRuleSets = new HashMap<Locale, String>();
        rbnfRuleSets.put(Locale.US, ruleSet_en_US);
        rbnfRuleSets.put(new Locale("th"), ruleSet_th_TH);
    }