It's useful trick in situation when you need to sort certain groups of data. Preserve chronological order of items inserted in Heap. Good use-case is php_error_log. Each log entry has own majority of error. And it's usefull to sort file using max heap.

The soulution is - override default SplPriorityQueue

<?php
class OrderedPriority extends SplPriorityQueue
{
    protected $serial = PHP_INT_MAX;

    public function insert($value, $priority)
    {
        parent::insert($value, array($priority, $this->serial--));
    }
}

function setPriority($line) {
    $start = strpos($line, 'PHP');
    $end = strpos($line, ':', $start);
    $error = substr($line, $start, $end-$start);

    switch ($error) {
        case 'PHP Fatal error':
        case 'PHP Catchable fatal error':
            return 10;
        case 'PHP Warning':
            return 8;
        case 'PHP Deprecated':
            return 7;
        case 'PHP Parse error':
            return 5;
        case 'PHP Notice':
            return 2;
        default:
            return 0;
    }
}

$log = new OrderedPriority(); // SplPriorityQueue can be here, but then we'll lose chronolocial order
$file = new SplFileObject('php_error_log');

while (!$file->eof()) {
    $line = $file->fgets();
    $log->insert($line, setPriority($line));
}

while (!$log->isEmpty()) {
    echo $log->extract() . '<br>';
}