@Override
 public String toString() {
   StringBuffer buffer = new StringBuffer();
   buffer.append("[AtomFeed ");
   if (id != null) {
     buffer.append("id:" + id + "\n");
   }
   if (updated != null) {
     buffer.append("updated:" + updated + "\n");
   }
   if (title != null) {
     buffer.append("title:" + title.toString());
   }
   if (rights != null) {
     buffer.append("rights:" + rights.toString());
   }
   if (subtitle != null) {
     buffer.append("subtitle:" + subtitle.toString());
   }
   if (generator != null) {
     buffer.append("generator:" + generator + "\n");
   }
   if (icon != null) {
     buffer.append("icon:" + icon + "\n");
   }
   if (logo != null) {
     buffer.append("logo:" + logo + "\n");
   }
   for (AtomPerson author : authors) {
     buffer.append(author.toString());
   }
   for (AtomPerson contributor : contributors) {
     buffer.append(contributor.toString());
   }
   for (AtomCategory category : categories) {
     buffer.append(category.toString());
   }
   for (AtomLink link : links) {
     buffer.append(link.toString());
   }
   for (AtomEntry entry : entries) {
     buffer.append(entry.toString());
   }
   buffer.append("]\n");
   return buffer.toString();
 }
 @Override
 public String toString() {
   StringBuffer buffer = new StringBuffer();
   buffer.append("[AtomEntry ");
   if (id != null) {
     buffer.append("id:" + id + " ");
   }
   if (published != null) {
     buffer.append("published:" + published + " ");
   }
   if (updated != null) {
     buffer.append("updated:" + updated + " ");
   }
   if (title != null) {
     buffer.append("title:" + title + " ");
   }
   for (AtomPerson atomPerson : authors) {
     buffer.append(atomPerson.toString());
   }
   for (AtomPerson atomPerson : contributors) {
     buffer.append(atomPerson.toString());
   }
   for (AtomCategory category : categories) {
     buffer.append(category.toString());
   }
   for (AtomLink atomLink : links) {
     buffer.append(atomLink.toString());
   }
   for (AtomContent atomContent : contents) {
     buffer.append(atomContent.toString());
   }
   for (AtomReplyTo atomRecipient : recipients) {
     buffer.append(atomRecipient.toString());
   }
   buffer.append("]");
   return buffer.toString();
 }
 private boolean hasTag(String scheme, String term) {
   for (AtomCategory tag : getTags()) {
     if (scheme.equals(tag.getScheme()) && term.equals(tag.getTerm())) return true;
   }
   return false;
 }