How to use the aws-lambda-graphql.withFilter function in aws-lambda-graphql

await pubSub.publish('NEW_MESSAGE', payload);

      return payload;
    },
  },
  Query: {
    serverTime: () => Date.now(),
  },
  Subscription: {
    messageFeed: {
      resolve: (rootValue: Message) => {
        // root value is the payload from sendMessage mutation
        return rootValue;
      },
      subscribe: withFilter(
        pubSub.subscribe('NEW_MESSAGE'),
        (rootValue: Message, args: { type: null | MessageType }) => {
          // this can be async too :)
          if (args.type == null) {
            return true;
          }

          return args.type === rootValue.type;
        },
      ),
    },
  },
};

const server = new Server({
  connectionManager,