code: function () {
  
      var writeStream = fs.createWriteStream('/dev/null'),
          readStream = fs.createReadStream('/dev/null');
  
      return repl.start({
        prompt: format('kona~%s > ', this.version),
        useColors: true,
        input: this.env === 'test' ? readStream : process.stdin,
        output: this.env === 'test' ? writeStream : process.stdout
      });
  
    }
docs: starts the kona repl