class Configuration implements Iterable<Map.Entry<String,String>>,
                                      Writable {

  public void setPattern(String name, Pattern pattern) {
    assert pattern != null : "Pattern cannot be null";
    set(name, pattern.pattern());
  }

  public  Configuration();
  public  Configuration(boolean loadDefaults);
  @SuppressWarnings("unchecked") public  Configuration(Configuration other);

}