HtmlCleaner is a project originally developed by Vladimir Nikic (http://htmlcleaner.sourceforge.net/).

This version is modified by iSharkFly.

Briefly speaking, the modifications are

* Added *final* keyword to variables if possible, to avoid memory leaks
* Changed some methods for better performance
* Add new class *FastHtmlSerializer* to output the HTML tree non-recursively, to avoid stack overflow (especially for Android)
* Other minor changes 

Author: iSharkFly (https://www.isharkfly.com/c/computer-program/java/15).