text: // const Koa = require('koa');
  const Koa = require('../lib/koa');
  const app = new Koa();
  const port = 8080;
  
  app.use((ctx, next) => {
      ctx.body = 'hello koa';
  });
  
  app.listen(port, () => {
      console.log(`${port} listening`);
  });