code: private static Optional<ICondition> asContainsNone( JsonObject json)
      {
      return
        json.containsKey( HAS_NONE_KEY)
        ? Optional.of( new Not( new ContainsAny( toIdentifiers( json.getJsonArray( HAS_NONE_KEY)))))
        : Optional.empty();
      }
docs: Returns the Not( ContainsAny) condition represented by the given JSON object or an empty
  value if no such condition is found.