Best practice to create php singleton

Singleton.php

<?php
trait Singleton {
    static private $instance = null;

    private function __construct() { /* ... @return Singleton */ }  // Protect from creation through new Singleton
    private function __clone() { /* ... @return Singleton */ }  // Protect from creation through clone
    private function __wakeup() { /* ... @return Singleton */ }  // Protect from creation through unserialize

    static public function getInstance() {
		return 
		self::$instance===null
			? self::$instance = new static()//new self()
			: self::$instance;
    }
}

/**
 * Class Foo
 * @method static Foo getInstance()
 */
class Foo {
    use Singleton;

    private $bar = 0;

    public function incBar() {
        $this->bar++;
    }

    public function getBar() {
        return $this->bar;
    }
}

/*
Use
*/

$foo = Foo::getInstance();
$foo->incBar();

var_dump($foo->getBar());

$foo = Foo::getInstance();
$foo->incBar();

var_dump($foo->getBar());
?>