anchor.diff:  
     for (int i = 0; i < whiteSpace.length; i++) {
       var ws = whiteSpace[i];
  -    print(ws.codeUnitAt(0).toRadixString(16));
       Expect.equals(0, int.parse("${ws}0${ws}", radix: 2));
     }
   
  
positive.code:   Expect.throws(() => int.parse("9", radix: 8, onError: () => 42));
    Expect.throws(() => int.parse("9", radix: 8, onError: (v1, v2) => 42));
  }
  
negative.code:   void testFails(String source, int radix) {
      Expect.throws(() { throw int.parse(source, radix: radix,
                                         onError: (s) { throw "FAIL"; }); },
                    isFail,
                    "$source/$radix");
      Expect.equals(-999, int.parse(source, radix: radix, onError: (s) => -999));
    }
    for (int i = 2; i < 36; i++) {
      var char = i.toRadixString(36);
      testFails(char.toLowerCase(), i);
      testFails(char.toUpperCase(), i);
    }
    testFails("", 2);
    testFails("+ 1", 2);  // No space between sign and digits.
  