D365FO Copy document from table to another

public static void copyDocuRef(smmActivities _smmActivitiesFrom, smmActivities _smmActivitiesTo)
    {
        DocuRef smmActivitiesFromDocuRef;

        while select  smmActivitiesFromDocuRef
            where   smmActivitiesFromDocuRef.RefTableId     == tableNum(smmActivities)
            &&      smmActivitiesFromDocuRef.RefRecId      == _smmActivitiesFrom.RecId
        {
            DocuRef::createFromDocuRef(smmActivitiesFromDocuRef, _smmActivitiesTo.RecId , tableNum(smmActivities));

        }
    }