LeadController::onModify

public function onModify($ownerID, array $params)
{
	if(!is_int($ownerID))
	{
		$ownerID = (int)$ownerID;
	}
	if($ownerID <= 0)
	{
		throw new Main\ArgumentException('Owner ID must be greater than zero.', 'ownerID');
	}

	$currentFields = isset($params['CURRENT_FIELDS']) && is_array($params['CURRENT_FIELDS'])
		? $params['CURRENT_FIELDS'] : array();
	$previousFields = isset($params['PREVIOUS_FIELDS']) && is_array($params['PREVIOUS_FIELDS'])
		? $params['PREVIOUS_FIELDS'] : array();

	$fieldsMap = $params['FIELDS_MAP'] ?? null;
	if (is_array($fieldsMap))
	{
		$currentFields = EntityFieldsHelper::replaceFieldNamesByMap($currentFields, $fieldsMap);
		$previousFields = EntityFieldsHelper::replaceFieldNamesByMap($previousFields, $fieldsMap);
	}

	$prevStatusID = isset($previousFields['STATUS_ID']) ? $previousFields['STATUS_ID'] : '';
	$curStatusID = isset($currentFields['STATUS_ID']) ? $currentFields['STATUS_ID'] : $prevStatusID;

	$authorID = self::resolveEditorID($currentFields);

	$historyEntryID = 0;
	if($prevStatusID !== $curStatusID)
	{
		$statusNames = \CCrmLead::GetStatusNames();
		$historyEntryID = ModificationEntry::create(
			array(
				'ENTITY_TYPE_ID' => \CCrmOwnerType::Lead,
				'ENTITY_ID' => $ownerID,
				'AUTHOR_ID' => $authorID,
				'SETTINGS' => array(
					'FIELD' => 'STATUS_ID',
					'START' => $prevStatusID,
					'FINISH' => $curStatusID,
					'START_NAME' => isset($statusNames[$prevStatusID]) ? $statusNames[$prevStatusID] : $prevStatusID,
					'FINISH_NAME' => isset($statusNames[$curStatusID]) ? $statusNames[$curStatusID] : $curStatusID
				)
			)
		);
	}
	$this->sendPullEventOnAdd(new \Bitrix\Crm\ItemIdentifier(\CCrmOwnerType::Lead, $ownerID), $historyEntryID);

	$this->createManualOpportunityModificationEntryIfNeeded($ownerID, $authorID, $currentFields, $previousFields);
}