Singleton Pattern [PHP 8.1+]

Singleton.php

<?php

trait Singleton 
{
    /**
     * @var static[]
     */
    protected static $instances = [];

    /** 
     * @see https://refactoring.guru/design-patterns/singleton/php/example
     * 
     * @return static
    */
    public static function instance(): static
    {
        return static::$instances[static::class] ??= new static();
    }

    /** 
     * @see https://www.php.net/manual/en/language.oop5.decon.php#object.construct
     * 
     * @return void
    */
    protected function __construct(){}

    /**
     * @see https://www.php.net/manual/en/language.oop5.cloning.php#object.clone
     * 
     * @return void
    */
    protected function __clone(){}
    
    /**
     * @see https://www.php.net/manual/en/language.oop5.magic.php#object.sleep
     * 
     * @return void
    */
    protected function __sleep(){}
    
    /** 
     * @see https://www.php.net/manual/en/language.oop5.magic.php#object.wakeup
     * 
     * @return void
    */
    protected function __wakeup(){}
}