CBPDocumentService::updateDocument

public function updateDocument($parameterDocumentId, $arFields, $modifiedBy = null)
{
	[$moduleId, $entity, $documentId] = CBPHelper::ParseDocumentId($parameterDocumentId);

	$this->clearCache();

	if ($moduleId)
	{
		CModule::IncludeModule($moduleId);
	}

	if (class_exists($entity))
	{
		$modifiedById = $modifiedBy ? CBPHelper::ExtractUsers($modifiedBy, $parameterDocumentId, true) : null;
		return call_user_func_array([$entity, 'UpdateDocument'], [$documentId, $arFields, $modifiedById]);
	}

	return false;
}