These files are the classes used in most of the PocketMine PHP projects. They are required for the code to work.
PocketMine Standard PHP Library
Copyright (C) 2014-2018 PocketMine Team <https://github.com/PocketMine/PocketMine-SPL>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.