code: private Entity parseResourceRef(final EntitySet set, final Node n) throws ResourceXMLParserException {
          final Node node2 = n.selectSingleNode("@" + COMMON_NAME);
          if (null == node2) {
              throw new ResourceXMLParserException("@" + COMMON_NAME + " required: " + reportNodeErrorLocation(n));
          }
          final String rname = node2.getStringValue();
          return set.getOrCreateEntity( rname);
      }
docs: Parse a simple resource/entity node for the type/name attributes, returning a new or existing Entity
  
  @param set entity set
  @param n   entity DOM node
  
  @return new or existing Entity
  
  @throws ResourceXMLParserException if the ndoe is missing the required attributes