<?php $expectedCommonVariables = array_merge($expectedCommonVariables, $overriddenKeys);
self::assertArraySubset($expectedCommonVariables, $response['$_SERVER']);
$keysToRemove = array_keys(array_diff_key($expectedCommonVariables, $overriddenKeys));
foreach ($keysToRemove as $keyToRemove) {
unset($response['$_SERVER'][$keyToRemove]);
}