private ILocker GetAvailableLocker(Size size)
{
ILocker result = null;
if (size == Size.Small && SmallLockers.Count > 0)
{
result = SmallLockers.Dequeue();
}
if (result == null && size == Size.Medium && MediumLockers.Count > 0)
{
result = MediumLockers.Dequeue();
}
if (result == null && size == Size.Large && LargeLockers.Count > 0)
{
result = LargeLockers.Dequeue();
}
if (result == null && size == Size.XLarge && XLargeLockers.Count > 0)
{
result = XLargeLockers.Dequeue();
}
if (result == null)
{
throw new Exception("All lockers are full");
}
return(result);
}