code: public String getPathName(int accessor) {
      JMFFieldDef field = getFieldDef(accessor);
      if (field == null)
        return null;
      if (field instanceof JSVariant && ((JSVariant)field).getBoxed() != null)
        return null;
      return getPathName(field);
    }
docs: Return the most informative possible path name for an accessor
  
  @param accessor the accessor for which path name information is desired
  @return the desired path name or null if the accessor is invalid (note that null is a
  valid accessor for the root type if the root type is a field; however, "" is an
  equivalent accessor and that is what is returned for that case).  For purposes of
  this method, an accessor that refers to a variant box is "invalid" (it is designed
  only for internal use, and this method is designed for more public use).