Task::getChanges

private function getChanges(array $fields): array
{
	$taskData = $this->getFullTaskData();
	if (!$taskData)
	{
		return [];
	}

	if (isset($taskData['DURATION_PLAN']))
	{
		unset($taskData['DURATION_PLAN']);
	}
	if (isset($fields['DURATION_PLAN']))
	{
		// at this point, $arFields['DURATION_PLAN'] in seconds
		$fields['DURATION_PLAN_SECONDS'] = $fields['DURATION_PLAN'];
		unset($fields['DURATION_PLAN']);
	}

	return CTaskLog::GetChanges($taskData, $fields);
}