WordprocessingMLPackage clonePkg = (WordprocessingMLPackage)this.getPackage().clone(); // consistent with MergeDocx approach
JaxbXmlPartAltChunkHost clonedPart = (JaxbXmlPartAltChunkHost)clonePkg.getParts().get(partName);
List<Object> contentList = ((ContentAccessor)clonedPart).getContent();
AltChunkFinder bf = new AltChunkFinder();
new TraversalUtil(contentList, bf);
CTAltChunk altChunk;
boolean encounteredDocxAltChunk = false;
for (LocatedChunk locatedChunk : bf.getAltChunks()) {
altChunk = locatedChunk.getAltChunk();
AlternativeFormatInputPart afip
= (AlternativeFormatInputPart)clonedPart.getRelationshipsPart().getPart(
altChunk.getId() );