Add following packages to composer.json file next to drupal repository

Edit bashrc file (~/.bashrc)

PHP Class using StringTranslationTrait

StringTranslationTrait allow to get t() and formatPlural() methods
Example:
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\StringTranslation\TranslationInterface;
class MyClass {


Import configuration file programmatically on Drupal 9 using config_update contrib module and service

//Update Module settings
\Drupal::service('config_update.config_update')->revert('system.simple', 'mymodule.settings');

State servic eallow to store variables such as state of the server temporarily or permanently

Examples: