Generate & Download PDF of Invoice

[dweep119]

Hey I am trying your code to generate and download PDF of particular invoice ID, but I am facing some problem.
My Code like this:-

var xero = new Xero(CONSUMER_KEY, CONSUMER_SECRET, RSA_PRIVATE_KEY);
var invoiceId = xxxxxxxxxxxxxxxxxxxx;
var req = xero.call('GET', '/Invoices/' + invoiceId);

req.setHeader('Accept', 'application/pdf');
req.on('response', function(response) {
console.log("Response");
var file = fs.createWriteStream(invoiceId + '.pdf');
response.pipe(file);
console.log("Response after cerateing File");
});
req.end();

Both console.log messages printed but doesn't return anything and Browser continuous loading.
Is there any mistake??
How should I Download pdf of invoice??