code: public Tune getTune(int referenceNumber) {
  		Object o = m_tunes.get(new Integer(referenceNumber));
  		if (o != null)
  			return (Tune) o;
  		else
  			return null;
  	}
docs: Returns the tune requested by its reference number. <br>
  Returns null if ref number is not found
  
  @return a Tune or null