Added return statement if there is a uri tag set. There is no need to go further in that case.
Added extra if-statement with error message if localName contains a null value or is undefined. This case can happen if the OSLO editor adds a name tag to the diagram, but does not provide a value for it.
uritag set. There is no need to go further in that case.localNamecontains anullvalue or isundefined. This case can happen if the OSLO editor adds anametag to the diagram, but does not provide a value for it.