anchor.diff:  import 'dart:json' as json;
   
   var verbose = false;
  +var testName = null;
   
   main() {
  +	var args = new Options().arguments;
  +	if (!args.isEmpty) {
  +		for (var arg in args) {
  +			if (arg == '--verbose' || arg == '-v') {
  +				verbose = true;
  +			} else if (arg.startsWith('-')) {
  +				print('Unknown argument: $arg');
  +				print('Usage: dart test/mustache_spec_test.dart [--verbose] [test name]');
  +				return;
  +			} else {
  +				testName = arg;
  +				verbose = true;
  +			}
  +		}
  +	}
  +
   	var specs = new Directory('test/spec')
   		.listSync()
   		.where((f) => f is File && f.path.endsWith('.json'));
  
positive.code: }
  
  runTest(String name, String desc, Map data, String template, String expected) {
  	var output;
  	var exception;
  	try {
  
negative.code: 	var result = passed ? 'Pass' : 'Fail';
  	print('    $result  $name');
  	if (verbose && !passed) {
  		print(desc);
  		print('        Template: $template');
  		print('        Data:     ${json.stringify(data)}');
  		print('        Expected: $expected');
  		print('        Output:   $output');
  		if (exception != null) print('        Exception: $exception'); // TODO stack trace.
  		print('');
  		print('');
  	}
  }
  
  