read position accountingReference

To new field ReceivableSpecifiedTradeAccountingAccount

library/src/main/java/org/mustangproject/Item.java

@@ -42,6 +42,7 @@ public class Item implements IZUGFeRDExportableItem {
 	protected ArrayList<IZUGFeRDAllowanceCharge> Allowances = new ArrayList<>();
 	protected ArrayList<IZUGFeRDAllowanceCharge> Charges = new ArrayList<>();
 	protected List<IncludedNote> includedNotes = null;
+	protected String accountingReference;
 	//protected HashMap<String, String> attributes = new HashMap<>();
 
 	/***
@@ -214,6 +215,8 @@ public class Item implements IZUGFeRDExportableItem {
 
 			icnm.getAllNodes("AdditionalReferencedDocument").map(ReferencedDocument::fromNode).forEach(this::addAdditionalReference);
 
+			icnm.getAsString("ReceivableSpecifiedTradeAccountingAccount").ifPresent(s -> this.accountingReference = s == null ? null : s.trim());
+
 			icnm.getAsNodeMap("BillingSpecifiedPeriod").ifPresent(periodNode -> {
 				Date start = periodNode.getAsNodeMap("StartDateTime").flatMap(dateTimeNode -> dateTimeNode.getNode("DateTimeString")).map(dts -> XMLTools.tryDate(dts)).orElse(null);
 				Date end = periodNode.getAsNodeMap("EndDateTime").flatMap(dateTimeNode -> dateTimeNode.getNode("DateTimeString")).map(dts -> XMLTools.tryDate(dts)).orElse(null);
@@ -538,4 +541,9 @@ public class Item implements IZUGFeRDExportableItem {
 	public List<IncludedNote> getNotesWithSubjectCode() {
 		return includedNotes;
 	}
+
+	@Override
+	public String getAccountingReference() {
+		return accountingReference;
+	}
 }

library/src/main/java/org/mustangproject/ZUGFeRD/IZUGFeRDExportableItem.java

@@ -172,4 +172,8 @@ public interface IZUGFeRDExportableItem extends IAbsoluteValueProvider{
 	default List<IncludedNote> getNotesWithSubjectCode() {
 		return null;
 	}
+
+	default String getAccountingReference() {
+		return null;
+	}
 }