UnsignedNumberUtil { public static String unsignedLongToString(long x) { return unsignedLongToString(x, 10); } private  UnsignedNumberUtil(); static int parseUnsignedInt(String s); static String unsignedIntToString(int x); static long parseUnsignedLong(String s); static String unsignedLongToString(long x); static final long MAX_VALUE; }
@Test public void testUnsignedLongToString() throws Exception { Assert.assertEquals("18446744073709551615", UnsignedNumberUtil.unsignedLongToString(-1L)); }