parseInputs method
- @override
- GamepadState state
override
    Return a list of commands based on the current state of the gamepad.
Implementation
@override
List<Message> parseInputs(GamepadState state) => [
  DriveCommand(throttle: throttle, setThrottle: true),
  DriveCommand(setLeft: true, left: state.normalLeftY),
  DriveCommand(setRight: true, right: -1*state.normalRightY),
];