public override bool ApplyPower(int voltage)
        {
            var regulatedVoltage = Regulate(voltage);

            // this is where the interface is adapted "ApplyPower" becomes "On"
            _americanPlug.On(regulatedVoltage);

            return(true);
        }
 public override bool ApplyPower(int voltage)
 {
     // this is where the interface is adapted "ApplyPower" becomes "On"
     return(_americanPlug.On(voltage));
 }