CommentReader::getUserNames

private function getUserNames(array $users): array
{
	if (empty($users))
	{
		return [];
	}

	$usersToFind = array_flip(array_diff_key(array_flip($users), static::$userNames));

	if (!empty($usersToFind))
	{
		$userNames = User::getUserName($usersToFind);
		foreach ($userNames as $userId => $userName)
		{
			static::$userNames[$userId] = $userName;
		}
	}

	return array_intersect_key(static::$userNames, array_flip($users));
}