public bool AddCheque(DrawerFlag _flag, int _id, int _managerid, int _employeeid, Cheque _cheque) { lock (this.syncRoot) { CashDrawer _drawer = null; if (TryGetDrawer(_flag, out _drawer, _id, _managerid, _employeeid)) { return(_drawer.AddCheque(_cheque)); } return(false); } }