code: public static String getProperty(final MessageResources msg,
                                     final String pname,
                                     final String def) throws Throwable {
      String p = msg.getMessage(pname);
      if (p == null) {
        return def;
      }
  
      return p;
    }
docs: Return a property value or the default
  
  @param msg      MessageResources object
  @param pname    String name of the property
  @param def      String default value
  @return String  property value or default (may be null)
  @throws Throwable on error