Update::isItemChanged

protected function isItemChanged(): bool
{
	if($this->isItemChanged === null)
	{
		$this->isItemChanged = (
			$this->item->isChanged('STAGE_ID') ||
			!empty($this->item->getChangedUserFieldNames())
		);

		if ($this->isItemChanged)
		{
			$this->historyItem = clone $this->item;
		}
	}

	return $this->isItemChanged;
}