public void ExtendTo(int min, int max)
{
IntRange intRange = new IntRange(min, max);
if (!intRange.IsSubrange(Range))
{
throw new Exception("Cannot extend to a smaller range.");
}
for (int i = min; i <= max; i++)
{
if (!function.ContainsKey(i))
{
function.Add(i, i);
}
}
Range = intRange;
}