How to inculde 3d parrty libraries into your module? I am using the 3d party php library, and I do not know how to connect. The file structure of my project looks like following: 

-my_project
--src
---Plugin
----Action
-----MyAction.php
---libs
----mylibs
-----src
------ClassWhichINeed.php

--my_project.info.yml


So I need to connect ClassWhichINeed.php to MyAction.php. 
In ClassWhichINeed.php I specified namespace as Drupal\my_project\mylibs;

And in MyAction.php i use Drupal\my_project\mylibs;

But when I create 
$object = new ClassWhichINeed;

I get an error "Undefiened class"
suggestion:

in MyAction.php add: 

require_once DRUPAL_ROOT . '/modules/my_project/src/libs/mylibs/src/ClassWhichINeed.php';