# File lib/preferences.rb, line 318
  def save
    metadata.each do |obj_id, md|
      obj = ObjectSpace._id2ref(obj_id) rescue nil
      copy_prefs(obj, md) if obj and md.connected
    end
    
    write_pref_file(preferences)
  rescue StandardError => e
    raise SaveError, e.message, e.backtrace
  end