Function proxy

m3u8/vue.js:4618–4626

(target, sourceKey, key)

  };

  function proxy (target, sourceKey, key) {
    sharedPropertyDefinition.get = function proxyGetter () {
      return this[sourceKey][key]
    };
    sharedPropertyDefinition.set = function proxySetter (val) {
      this[sourceKey][key] = val;
    };
    Object.defineProperty(target, key, sharedPropertyDefinition);
  }

  function initState (vm) {
    vm._watchers = [];