buildschema from graphql throws 'TypeError: nodes.flatMap is not a function'

Question

Am using node version 10.24.0.

But when I try the example from the official site.

const graphql = require('graphql');

const schema = graphql.buildSchema(`
    type Query {
    hello: String
}`);

I get the following error.

TypeError: nodes.flatMap is not a function

Am using grapql@16.5.0

On the graphql official page, it says

Before getting started, you should have Node v6 installed, although the examples should mostly work in previous versions of Node as well.

So What can I do to get graphql to work here?