Invalid options provided to ApolloServer: costAnalysis is not a function

[ShigeruNakagaki]

I'm trying to use graphql-cost-analysis. but it just said costAnalysis is not a function.
I can not show you entire code. but it's like this.

const { graphqlExpress } = require('graphql-server-express');
const costAnalysis = require('graphql-cost-analysis')
...
      graphqlExpress(req => {
        return {
          schema,
          rootValue: null,
          validationRules: [
            costAnalysis({
              variables: req.body.variables,
              maximumCost: 10
            }),
          ],
        }
      })
...

and the result of console.log(costAnalysis) is like this.

{ default: [Function: createCostAnalysis] }

What am I missing?

thanks

[mxstbr]

const costAnalysis = require('graphql-cost-analysis').default

[ShigeruNakagaki]

ahh, thank you!

I tried maximumCost: 1. the result was not what I expected.
It seems I need to study more about the configuration.

thank you again.