public void ChangesTvsStateToOnState()
{
// Arrange
IState on = new OnState();
Product tv = new Tv(on);
// Act
var theStateOfTv = tv.ChangeState();
// Assert
Assert.Equal("Current device's state is ON now.", theStateOfTv);
}
public void TurnsOnAndThenTurnsOffTheTv()
{
// Arrange
IState on = new OnState();
Product tv = new Tv(on);
// Act
var theStateOfTv = tv.ChangeState();
Assert.Equal("Current device's state is ON now.", theStateOfTv);
// Assert
var theStateOfTvIsOff = tv.ChangeState(new OffState());
Assert.Equal("Current device's state is OFF now.", theStateOfTvIsOff);
}