public void SetSold()
{
if (!CanSell())
{
throw new InvalidOperationException("Degree's state doesn't allow it to be sold.");
}
AvailabilityState = new SoldAvailabilityState();
}
public void Reserve()
{
if (!CanReserve())
{
throw new InvalidOperationException("Degree's state doesn't allow it to be reserved.");
}
AvailabilityState = new ReservedAvailabilityState();
}
public DegreeSnapshot(Degree degree)
{
_degree = degree;
_availabilityState = degree.AvailabilityState;
}
public void RemoveReservation()
{
AvailabilityState = new AvailableAvailabilityState();
}
public Degree(double degree)
{
_degree = degree;
AvailabilityState = new AvailableAvailabilityState();
}
public AvailabilityEventArgs(IAvailabilityState availabilityState) => NewState = availabilityState;
