Node's event emitter for ts.
oh 这只是一个练手的小玩具
ts + jest + rollup 实现EventBugs
var EventEmitter = require('events')
var ee = new EventEmitter()
ee.on('message', function (text) {
console.log(text)
})
ee.emit('message', 'hello world')
See the Node.js EventEmitter docs. events currently matches the Node.js 11.x API.