User::loadUser

private function loadUser(int $userId, array $fields): ?array
{
	$dbUsers = CUser::GetList(
		'id',
		'asc',
		['ID_EQUAL_EXACT' => $userId],
		[
			'FIELDS' => [
				'ID',
				'EMAIL',
				'WORK_PHONE',
				'PERSONAL_MOBILE',
				'PERSONAL_BIRTHDAY',
				'LOGIN',
				'ACTIVE',
				'NAME',
				'LAST_NAME',
				'SECOND_NAME',
				'WORK_POSITION',
				'PERSONAL_WWW',
				'PERSONAL_CITY',
			],
			'SELECT' => [
				'UF_DEPARTMENT',
				'UF_SKYPE',
				'UF_TWITTER',
				'UF_FACEBOOK',
				'UF_LINKEDIN',
				'UF_XING',
				'UF_WEB_SITES',
				'UF_PHONE_INNER',
				...array_keys($fields)
			]
		]
	);

	$user = $dbUsers->fetch();

	return is_array($user) ? $user : null;
}