Can't convince phpstan about existing offset

[ostrolucky]

self::assertArrayHasKey(1, $ubos);
self::assertFalse($ubos[1]->isActive);

produces

Offset 1 does not exist on array(MangoPay\Ubo).

related class: https://github.com/Mangopay/mangopay2-php-sdk/blob/d967b3fb6f45a0f01891134062265144950c9259/MangoPay/UboDeclaration.php

[ntzm]

As a workaround you can use

$this->assertTrue(array_key_exists('query', $urlParts));