// duynotes blog
public class IdleState implements State {
  public void insertDollar( VendingMachine vendingMachine ) {
    System.out.println( "dollar inserted" );
    vendingMachine.setState(vendingMachine.getHasOneDollarState());
  }
  public void ejectMoney( VendingMachine vendingMachine ) {
    System.out.println( "no money to return" );
}
  public void dispense( VendingMachine vendingMachine ) {
    System.out.println( "payment required" );
  }
}