text: // parent.js
  const cp = require('child_process');
  const path = require('path');
  const { Invoker } = require('../../../lib');
  
  const invokerChannel = cp.fork(path.join(__dirname, './child.js'));
  
  const invoker = new Invoker(invokerChannel);
  
  async function main() {
    const res1 = await invoker.invoke('sleep', 1000);
    console.log('sleep 1000ms:', res1);
    const res2 = await invoker.invoke('max', [1, 2, 3]); // 3
    console.log('max(1, 2, 3):', res2);
    invoker.destroy();
  }
  
  main();
  