code: public Set<String> keySet(){
  		HashSet<String> set=new HashSet<String>();
  		Iterator<String> keys=keys();
  		while(keys.hasNext()){
  			set.add(keys.next());
  		}
  		return set;
  	}
docs: Returns a set containing all keys on this object. If possible, use the keys iterator instead for improved performance.
  
  @return a set containing all keys in this object