Event.php

<?php
class Event
{
    protected static $events = [];

    public static function register(
        $name,
        $callable,
        $priority = 10
    ) {
        self::$events[$name][] = [$priority, $callable];
        uasort(
            self::$events[$name],
            fn ($a, $b) => $a[0] === $b[0] ? 0 : ($a[0] < $b[0] ? -1 : 1)
        );
    }

    public static function dispatch($name)
    {
        if (($ev = self::$events[$name]??null)) {
            array_map(
                'call_user_func',
                array_map(fn ($e) => $e[1], $ev)
            );
            return;
        }
        throw new RuntimeException(
            'Unregistered Event'
        );
    }
}