public Collection<URI> getURIAttributes() {
   Collection<RoughAttribute> roughAttributes = attributes.getValues();
   Collection<URI> values = new ArrayList<URI>();
   for (RoughAttribute attribute : roughAttributes) {
     if (attribute.hasURI()) {
       values.add(attribute.getURI());
     }
   }
   return values;
 }
 public Collection<String> getAttributeValueList(String attributeTypeName) {
   Collection<RoughAttribute> roughAttributes =
       attributes.getValues(new CaseInsensitiveString(attributeTypeName));
   Collection<String> values = new ArrayList<String>();
   for (RoughAttribute attribute : roughAttributes) {
     if (!attribute.hasURI()) {
       values.add(attribute.getValue());
     }
   }
   return values;
 }