code: function writeTxInfo(tokenInfo) {
    fs.writeFile("token-tx.json", JSON.stringify(tokenInfo, null, 2), function(
      err
    ) {
      if (err) return console.error(err)
      console.log(`token-tx.json written successfully.`)
    })
  }
docs: Write the TX info to a file, in case users need to retrieve it later. Note: it will be overwritten each time this example is executed.