text: 
  'use strict';
  
  const serve = require('./');
  const koa = require('koa');
  const app = koa();
  
  // $ GET /package.json
  // $ GET /
  
  app.use(serve('.'));
  
  app.use(function *(next){
    yield next;
    if ('/' == this.path) {
      this.body = 'Try `GET /package.json`';
    }
  })
  
  app.listen(3000);
  
  console.log('listening on port 3000');