code: public void initialize() {
      Enumeration		enm;
      String		superclass;
      String[]		packages;
  
      try {
        m_CacheNames   = new HashMap<>();
        m_ListNames    = new HashMap<>();
        m_CacheClasses = new HashMap<>();
        m_ListClasses  = new HashMap<>();
  
        enm = m_Packages.propertyNames();
        while (enm.hasMoreElements()) {
          superclass = (String) enm.nextElement();
          packages   = m_Packages.getProperty(superclass).replaceAll(" ", "").split(",");
          addHierarchy(superclass, packages);
        }
      }
      catch (Exception e) {
        getLogger().log(Level.SEVERE, "Failed to determine packages/classes:", e);
        m_Packages = new Properties();
      }
    }
docs: loads the props file and interpretes it.