Working with QueryResult in Workflow Expression

Hi,

please, can you help me with Workflow expression?

We are currently on Windchill 9.1.

I'm trying to export all assemblies from promotion and it's structure to text file (tsv).

Everything is working fine until I reach this line

versionedDoc = (wt.vc.Versioned)qrEPMDocumentMasters.nextElement();

I can not process the second QueryResult, I think it should be full of EPMDocumentMasters.

What am I doing wrong?

Thanks

try {
 wt.maturity.PromotionNotice pn = (wt.maturity.PromotionNotice)primaryBusinessObject;
 wt.fc.QueryResult qr = wt.maturity.MaturityHelper.service.getPromotionTargets(pn);
 wt.vc.Versioned tv = null;
 wt.epm.EPMDocument myDoc; 
 
 wt.fc.QueryResult qrEPMDocumentMasters;
 wt.vc.Versioned versionedDoc = null; 
 
 if (qr != null) {
 java.io.FileWriter outputStream = null;
 outputStream = new java.io.FileWriter("C:\\promotion\\EXPORT.tsv");
 try {
 while(qr.hasMoreElements()){
 
 tv = (wt.vc.Versioned)qr.nextElement();
 if (tv instanceof wt.epm.EPMDocument) {
 myDoc = (wt.epm.EPMDocument)tv; 
 
 if (myDoc.getDocType().getStringValue().equals("wt.epm.EPMDocumentType.CADASSEMBLY") && myDoc.isGeneric() != true) {
 
 outputStream.write("Assembly: " + myDoc.getCADName() + "\r\n"); 
 
 wt.query.QuerySpec querySpec = new wt.query.QuerySpec(wt.epm.EPMDocumentMaster.class, wt.epm.structure.EPMMemberLink.class); 
 
 qrEPMDocumentMasters = wt.epm.structure.EPMStructureHelper.service.navigateUses(myDoc, querySpec, true); 
 outputStream.write(qrEPMDocumentMasters.size() + " 1 \r\n");
 
 if (qrEPMDocumentMasters != null) {
 outputStream.write(qrEPMDocumentMasters.size() + " 2 \r\n");
 
 while (qrEPMDocumentMasters.hasMoreElements()) {
 versionedDoc = (wt.vc.Versioned)qrEPMDocumentMasters.nextElement();
 outputStream.write(qrEPMDocumentMasters.size() + " 3 \r\n");
 
 if (versionedDoc instanceof wt.epm.EPMDocumentMaster) {
 outputStream.write(qrEPMDocumentMasters.size() + " EPMDocumentMaster \r\n"); 
 }
 } 
 }
 } 
 }
 }
 
 } catch (Exception e) {
 e.printStackTrace();
 } 
 
 
 outputStream.close(); 
 }
 
 
} catch (Exception e) {
 e.printStackTrace(); 
}