text: const Koa = require('koa');
  const axios = require('axios');
  const app = new Koa();
  
  app.use(async ctx => {
    console.log("hello");
    await axios.get('http://sina.com')
    ctx.body = 'Hello World';
  });
  
  app.listen(8000);
  
  /**
  Server Software:        
  Server Hostname:        172.17.6.46
  Server Port:            8000
  
  Document Path:          /
  Document Length:        11 bytes
  
  Concurrency Level:      10
  Time taken for tests:   20.804 seconds
  Complete requests:      10
  Failed requests:        0
  Total transferred:      1470 bytes
  HTML transferred:       110 bytes
  Requests per second:    0.48 [#/sec] (mean)
  Time per request:       20803.929 [ms] (mean)
  Time per request:       2080.393 [ms] (mean, across all concurrent requests)
  Transfer rate:          0.07 [Kbytes/sec] received
  
  Connection Times (ms)
                min  mean[+/-sd] median   max
  Connect:        0    1   0.3      1       1
  Processing:  5882 7219 1797.6   6501   11324
  Waiting:     5881 7218 1797.4   6501   11323
  Total:       5882 7220 1797.6   6502   11325
  
  Percentage of the requests served within a certain time (ms)
    50%   6502
    66%   6627
    75%   7638
    80%   9480
    90%  11325
    95%  11325
    98%  11325
    99%  11325
   100%  11325 (longest request)
   */
  