/// <summary>
/// Computes the "unused land value."
/// If any structure cannot be built in this cube. returns null.
/// </summary>
public ULV create(Cube cube)
{
ULV ulv = (ULV)ULVs[cube];
if (ulv == null)
{
ULVs[cube] = ulv = ULV.create(cube);
}
return(ulv);
}
protected Plan(ULV ulv)
{
this.ulv = ulv;
}