NodeJS and PDFkit: 'margin' property gives "Unexpected identifier" error? - node.js

Question

I have successfully gotten my code to output a pdf, but when I attempt to adjust the margins using the 'margin' property listed in the documentation using the following code,
var pdf = require ('pdfkit');
var fs = require('fs');
var doc = new pdf(
{
size: [288,144]
}
);
doc.pipe(fs.createWriteStream('run.pdf'));
doc.font('Times-Roman')
.text('Hello different Times Roman!')
doc.addPage({
size: [288,144]
margin : 10
});
doc.end();
I get this error:
margin : 10
^^^^^^
SyntaxError: Unexpected identifier
at exports.runInThisContext (vm.js:53:16)
at Module._compile (module.js:373:25)
at Object.Module._extensions..js (module.js:416:10)
at Module.load (module.js:343:32)
at Function.Module._load (module.js:300:12)
at Function.Module.runMain (module.js:441:10)
at startup (node.js:139:18)
at node.js:974:3
Am I missing something obvious here?

Answer 1

Just to ensure any future reader come here with this specific problem, this is a JavaScript Object. When listing JavaScript Objects, every property must be followed by a , except the last instance.
As an example, this:
doc.addPage({
size: [288,144]
margin : 10
});
becomes this:
doc.addPage({
size: [288,144],
margin : 10
});