Setup RelayNetworkLogger with relay-runtime v6

environment.js

import { Network } from 'relay-runtime'

import createRelayNetworkLogger from 'relay-runtime/lib/network/createRelayNetworkLogger'
import RelayNetworkLoggerTransaction from 'relay-runtime/lib/network/RelayNetworkLoggerTransaction'

import cacheHandler from './cacheHandler'

const RelayNetworkLogger = createRelayNetworkLogger(RelayNetworkLoggerTransaction)

const network = Network.create(
  process.env.NODE_ENV === 'development' ? RelayNetworkLogger.wrapFetch(cacheHandler) : cacheHandler
)