public AttachmentPart getAttachment(java.net.URI ref, Iterator iter) {
   if (iter == null || ref == null) {
     System.err.println("getAttachment: null Iterator for AttachmentPart");
     return null;
   }
   while (iter.hasNext()) {
     AttachmentPart tempAttachment = (AttachmentPart) iter.next();
     if (ref.isOpaque() && ref.getScheme().equals("cid")) {
       String refId = ref.getSchemeSpecificPart();
       String cId = tempAttachment.getContentId();
       if (cId.equals("<" + refId + ">") || cId.equals(refId)) {
         return tempAttachment;
       }
     }
   }
   return null;
 }