* @return The Relationship
*/
public Relationship addPart(Part part, AddPartBehaviour mode,
ContentTypeManager ctm, String relId) throws InvalidFormatException {
PartName newPartName = part.getPartName();
log.info("adding part with proposed name: " + newPartName.getName());
if (this.getPackage().getParts().get( newPartName )!=null) {
if (mode.equals(AddPartBehaviour.REUSE_EXISTING)) {