old_contents: const ytdl = require('..');
  
  const stream = ytdl('https://www.youtube.com/watch?v=2UBFIhS1YBk', {
    requestOptions: (parsed) => {
      return {
        host: '127.0.0.1',
        port: 8888,
        path: '/' + parsed.href,
        headers: { Host: parsed.host },
      };
    },
  });
  
  console.log('Starting Download');
  
  stream.on('data', (chunk) => {
    console.log('downloaded', chunk.length);
  });
  
  stream.on('end', () => {
    console.log('Finished');
  });
new_contents: const ytdl = require('..');
  
  const stream = ytdl('https://www.youtube.com/watch?v=2UBFIhS1YBk', {
    requestOptions: {
      transform: (parsed) => {
        return {
          host: '127.0.0.1',
          port: 8888,
          path: '/' + parsed.href,
          headers: { Host: parsed.host },
        };
      },
    }
  });
  
  console.log('Starting Download');
  
  stream.on('data', (chunk) => {
    console.log('downloaded', chunk.length);
  });
  
  stream.on('end', () => {
    console.log('Finished');
  });
  
subject: Fix proxy example to actually transform URL (#227)