code: function(localImagePath) {
          // Read the file in and convert it.
        var imageFile = fs.readFileSync(localImagePath);
        var mimeType = mime.lookup(localImagePath);
        var ret = "data:";
        ret += mimeType;
        ret += ";base64,";
        ret += imageFile.toString("base64");
        return ret;
    }
docs: Given the path for an image in the local file system, returns a data URI string
  representing the data in that image file.