Configure oauth package to work with Xero API

gistfile1.js

// Xero API defaults to application/xml content-type
var customHeaders = {
  "Accept" : "application/json",
  "Connection": "close"
};

var oauth = new OAuth.OAuth(
    REQUEST_URL,
    ACCESS_URL,
    CONSUMER_KEY,
    CONSUMER_SECRET,
    '1.0A',
    null,
    'HMAC-SHA1',
    null,
    customHeaders
);

// This is important - Xero will redirect to this URL after successful authentication
// and provide the request token as query parameters
oauth._authorize_callback=CALLBACK_URL;