How to use the react-relay-network-modern.cacheMiddleware function in react-relay-network-modern

export function createRelayEnvironment(cache) {
  const isServer = typeof window === 'undefined'

  const relaySSRMiddleware = isServer
    ? new RelayServerSSR()
    : new RelayClientSSR(cache) // eslint-disable-line

  relaySSRMiddleware.debug = false

  const network = new RelayNetworkLayer([
    relaySSRMiddleware.getMiddleware({
      lookup: true,
    }),
    cacheMiddleware({
      size: 100, // max 100 requests
      ttl: 900000, // 15 minutes
      onInit: cache => {
        // TODO: Handle this cache
        // console.log(cache)
      },
    }),
    urlMiddleware({
      url: process.env.METAPHYSICS_BASE_URL,
    }),
    // loggerMiddleware(),
  ])

  const source = new RecordSource()
  const store = new Store(source)
  const environment = new Environment({

_createRelayNetworkLayer() {
    return new RelayNetworkLayer(
      [
        // batchMiddleware({
        //   batchUrl: '/graphql/batch',
        //   batchTimeout: 20,
        // }),
        cacheMiddleware({
          size: 100,
          ttl: 15 * 60 * 1000, // 15 minutes
          onInit: cache => (this._cache = cache),
        }),
        urlMiddleware({
          url: this.endpoint,
        }),
        __DEV__ ? loggerMiddleware() : null,
        // __DEV__ ? perfMiddleware() : null,
        !__DEV__
          ? retryMiddleware({
              // [3200, 6400, 12800, 25600, 51200, 102400, 204800, 409600, ...],
              retryDelays: attempt => 2 ** (attempt + 4) * 100,
              forceRetry: (cb, delay) => {
                window.forceRelayRetry = cb;
                // eslint-disable-next-line