code: public static String fieldNodeFormat(Collection<FieldNode> fieldNodes) {
  		StringBuilder s = new StringBuilder();
  		int n = 0;
  		for (FieldNode fieldNode : fieldNodes) {
  			if (n > 0) {
  				s.append(" ");
  			}
  			s.append("'").append(fieldNodeFormat(fieldNode)).append("'");
  			n++;
  		}
  		return s.toString();
  	}
docs: * value pair.