/*
   +----------+     
   | LongSong |     
   +----------+   
   +----------+   
*/   

// a predicate to select long songs
class LongSong implements ISelect{

  LongSong(){};

  //does the given song last more than 30 sec   
  public  boolean select(Object obj){ 
    return (((Song)obj).time>30); 
  } 
}