public String toString(){
  StringBuilder result=new StringBuilder("{ ");
  for (  Interval interval : intervals)   result.append(interval);
  result.append(" }");
  return result.toString();
}

public String toString ( ) { StringBuilder result = new StringBuilder ( "{ " ) ; for ( Interval interval : intervals ) result . append ( interval ) ; result . append ( " }" ) ; return result . toString ( ) ; }
make a string representation of this char set .
