Inter-window (cross-tab) communication library.
此脚本不应直接安装，它是供其他脚本使用的外部库。如果您需要使用该库，请在脚本元属性加入：// @require https://update.greasyfork.icu/scripts/405935/819599/IWC.js
I am not the author of this library. I am simply posting it here on Greasy Fork so that I can use it in one of my scripts.
Source: https://github.com/slimjack/IWC