code: function callback(err, hasError) {
  
      if (err !== null) {
          console.log(chalk.red('Error running JSHint over project: %j\n'), err);
      }
  
      if (hasError) {
          console.log(chalk.blue('\nSummary\n=======\n'));
          for (var errorCode in errors) {
              if (errors.hasOwnProperty(errorCode)) {
                  displaySummary(errorCode);
              }
          }
  
          console.log('');
  
          if (totalErrors > 1) {
              console.log(chalk.red('Found %d errors.\n'), totalErrors);
          } else {
              console.log(chalk.red('Found 1 error.\n'));
          }
      } else {
          console.log(chalk.green('No JSHint errors found.\n'));
      }
  }
docs: The callback is called when _JS Hint_ has finished parsing all files and is used to display a summary of all messages output.