ZUGFeRD2PullProvider adds null VATID

[swsch]

ZUGFeRD2PullProvider.java, lines 382 to 384 always add a <ram:SpecifiedTaxRegistration> element, although the spec states on p. 64 "Kardinalität 0..1", i.e. optional.

If you don't set the buyer's VATID, you get

        <ram:SpecifiedTaxRegistration> 
          <ram:ID schemeID="VA">null</ram:ID> 
        </ram:SpecifiedTaxRegistration> 

which in turn fails verification with ZUV (I wonder how DEnull would fare, though :-).

What do the comments //$NON-NLS-1$ in this neighbourhood mean?

If I were to touch this method generateXML, I probably could not refrain myself from using a StringBuilder and deleting the old (?) commented parts.

[jstaerk]

thanks, merged.
//$NON-NLS-1$
is the (eclipse) string literals silencer, e.g. if you localize (eclipse "externalize Strings") into .properties files

String abc="invoice"; //$NON-NLS-1$
will not ask for a translation for "invoice" because it is considered identical in all languages.