public static function init() {
		if ( ! isset( self::$instance ) && ! ( self::$instance instanceof Loader ) ) {
			self::$instance = new Loader();
			$modules        = array_merge( self::$available_modules, apply_filters( 'themeisle_sdk_modules', [] ) );
			foreach ( $modules as $key => $module ) {
				if ( ! class_exists( 'ThemeisleSDK\\Modules\\' . ucwords( $module, '_' ) ) ) {
					unset( $modules[ $key ] );
				}
			}
			self::$available_modules = $modules;
		}
	}