static void Postfix(BuildingRestriction __instance, ref bool __result, ref bool?__state)
 {
     if (__state ?? IsAvailable(__instance.GetType()))
     {
         __result = true;
     }
 }
 static bool Prefix(BuildingRestriction __instance, ref bool?__state)
 {
     if ((__state = IsAvailable(__instance.GetType())).Value)
     {
         return(false);
     }
     return(true);
 }