Using Meteor & GraphicsMagick

Question

I have Meteor v1 installed and GraphicsMagick installed.

When the app starts, the console tells me "GraphicsMagick found"

However when I try to follow these simple instructions: (https://github.com/aheckmann/gm/blob/master/README.md)

var fs = require('fs')
  , gm = require('./gm');

// resize and remove EXIF profile data
gm('/path/to/my/img.jpg')
.options({imageMagick: true})
.resize(240, 240)
...

I get "undefined is not a function" (referring to require('gm'))

Am I doing something wrong? How can I use GM in Meteor?