def mark_for_unload(const_desc)
      name = to_constant_name const_desc
      if explicitly_unloadable_constants.include? name
        return false
      else
        explicitly_unloadable_constants << name
        return true
      end
    end
def mark_for_unload(const_desc)
      name = to_constant_name const_desc
      if explicitly_unloadable_constants.include? name
        return false
      else
        explicitly_unloadable_constants << name
        return true
      end
    end
Mark the provided constant name for unloading. This constant will be
 unloaded on each request, not just the next one.