Weird behavior of iterator containing static class

[danog]

https://psalm.dev/r/c4714e538a

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/c4714e538a

<?php

/**
 * @template TTKey
 * @template TTValue
 * 
 * @extends ArrayObject<TTKey, TTValue>
 */
class iter extends ArrayObject {
    /**
     * @return self<TTKey, TTValue>
     */
    public function stabilize(): self {
        return $this;
    }
}

class a {
    /**
     * @return iter<int, static>
     */
    public function ret(): iter {
        return new iter([$this]);
    }
}
class b extends a {}

$a = (new a)->ret();
$a = $a->stabilize();
/** @psalm-trace $a */;

Psalm output (using commit 028ac7f):

INFO: Trace - 30:23 - $a: iter<int, a&iter<int, a&static>>

INFO: UnusedVariable - 29:1 - $a is never referenced or the value is not used