You will need to install a user script manager extension to install this script.
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive
// @require https://greasyfork.org/scripts/13980-html2canvas-custom-build-of-0-5-0-beta2/code/html2canvas%20-%20custom%20build%20of%20050-beta2.js?version=87728
Custom build for script #13805 (评论才是本体!)。