message: Adds refresh example
diff: @@ -109,6 +109,16 @@ const config = require('./config.json');
  const result = await xero.invoices.get();
  console.log('Number of invoices:', result.Invoices.length);
  + // You can refresh your access token when it's getting close to expiring
  + if((new Date) - accessToken.oauth_expires_at > 60*30*1000){
  + let newToken = await xero.oauth1Client.refreshAccessToken();
  + // Remember to store the new access token in your data store
  + }
  +
  + // The SDK will hold the latest acess token, so you can make more calls
  + const result1 = await xero.invoices.get();
  + console.log('Number of invoices:', result1.Invoices.length);
  +
  // When making future calls, you can initialise the Xero client direectly with the stored access token:
  const storedAccessToken = {
  