Foreach in a test. Ugh :/

test.php

<?php

/*
    $response->headers->all() = [
        'test' => ['test-value'],
        'Content-Type' => ['application/json'],
    ];
 */
$found = false;
foreach ($response->headers->all() as $key => $value) {
    if ($key === 'test' && $value[0] === 'test-value') {
        $found = true;
    }
}

$this->assertTrue($found);