def known_type?(key)
      return false unless key
      key &&= key.to_s.to_sym
      Rudy::ID_MAP.has_key?(key)
    end
def known_type?(key)
      return false unless key
      key &&= key.to_s.to_sym
      Rudy::ID_MAP.has_key?(key)
    end
Is the given +key+ a known type of object?