SOURCE

const bucket = new WeakMap()
console.log(bucket, 'bucket')
let target = { text: "hello" }
let depsMap = bucket.get(target)
console.log(depsMap, 'track函数里面的depsMap')
bucket.set(target, depsMap = new Map())
//depsMap是一个Map集合
console.log(bucket, '新创建的bucket')