lateinit var productionNumber: String
May be null. See spec for more info about nullability of this field.
ProductionNumber - serial number uniquely identifies instance of the Installation. It represents production number of cash register according to Swedish regulations. It has format "MK556{number}" where MK is mobilkassan, 556 is the beginning of the Produkt Poolen corporate ID, {number} - unique number within entire world
According to swedish regulation, the definition is: Each cash register must have a production number. Production number is a globally unique serial number on physical cash registers. Production number has to be unique for each cash register from one vendor and should also indicate vendor as a part of the field.