/** @return Returns the instruments. */
 public List getInstruments() {
   if (instruments == null || refresh == true) {
     instruments = instrumentDAO.getInstruments();
     refresh = false;
   }
   return instruments;
 }
 public Instrument getInstrument(Integer InstrumentID) {
   return instrumentDAO.getInstrument(InstrumentID);
 }
 public void saveInstrument(Instrument stock) throws Exception {
   instrumentDAO.saveInstrument(stock);
   refresh = true;
 }
 public Instrument getInstrument(String name) {
   return instrumentDAO.getInstrument(name);
 }