code: static public HashMap getErrorCodes ( Class clazz ) {
  
          HashMap map = new HashMap(23);
  
          // Use reflection to populte the erroCodeMap to have the reverse mapping
          // of error codes to symbolic names.
  
          Field flds[] = clazz.getDeclaredFields();
  
          for (int i = 0; i < flds.length; i++) {
              int mods = flds[i].getModifiers();
  
              if (Modifier.isFinal(mods) && Modifier.isStatic(mods) && Modifier.isPublic(mods)) {
                  try {
                      map.put(flds[i].get(null), flds[i].getName());
                  } catch (Throwable t) { // NOPMD
                      // ignore this.
                  }
              }
          }
          return map;
      }
docs: Return the codes that are defined on a subclass of our class.
  
  @param clazz  a class that is a subclass of us.
  @return a hashmap of int error codes mapped to the string names.